Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: TheBoy on 10 April 2007, 19:45:28
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Tunnie and I proved yesterday that the old radiator had a problem. We poured boiling water in it, and the middle section remained cold. We poured all sorts of stuff in it to clear blockage, and got loads of crap out. Running a hose through it showed it could cope with the flow of hosepipe on full. However, upon refitting, same problems with the car running too warm, and losing its coolant out of the cap.
So I bought a new rad today, fitted, but, yes, you guessed it, the problem remains >:(
The car is fine when gently driving around, but as soon as you start booting it, the temperature goes up to 95/96 (on the dash gauge), at which point I lift off a bit. It pops the cap and loses a cupful or so of coolant. If I gently drive home/somewhere safe, the cap may be slightly hissing, but removing cap shows no real pressure.
The middle of the gauge is 95 degrees. Omegatoy tells me that they should run 90 - 92 degrees.
I know the viscous fan may be problematic - but does this have much affect at 80mph (surely airflow should be enough??). The ECU is putting in substitute values for coolant temp due to an issue with the sensor/wiring.
Cooling aside, the engine appears faultless.
So far, I have replaced waterpump, thermostat, cap, and radiator.
I really, really am after some ideas and inspiration now.
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Only my 2 pennyworth......but it does sound a bit like it doesnt have enough pressure....temp will be hotter than the normal if not enough pressure....If you take the top off the coolant bottle when you have just stopped it and its still hot.....i would expect it to chuck hot water outa the bottle for a second....if you dont release the pressure gently.
Tho not enough pressure could be because of the hiss from the coolant bottle top....leaking the pressure.....are you sure that its a known good working top?
Is it the same as your MV6? ie could you swap them over to see what happens?
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Only my 2 pennyworth......but it does sound a bit like it doesnt have enough pressure....temp will be hotter than the normal if not enough pressure....If you take the top off the coolant bottle when you have just stopped it and its still hot.....i would expect it to chuck hot water outa the bottle for a second....if you dont release the pressure gently.
Tho not enough pressure could be because of the hiss from the coolant bottle top....leaking the pressure.....are you sure that its a known good working top?
Is it the same as your MV6? ie could you swap them over to see what happens?
Its not the cap from MV6 - that car is working and needs to stay that way. I have, however, tried 3 caps now....
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Only my 2 pennyworth......but it does sound a bit like it doesnt have enough pressure....temp will be hotter than the normal if not enough pressure....If you take the top off the coolant bottle when you have just stopped it and its still hot.....i would expect it to chuck hot water outa the bottle for a second....if you dont release the pressure gently.
Tho not enough pressure could be because of the hiss from the coolant bottle top....leaking the pressure.....are you sure that its a known good working top?
Is it the same as your MV6? ie could you swap them over to see what happens?
Its already had a replacement coolant bottle, bit of a bodge job as the V6 ones have extra pipes compared to the tractors.
Hummm new rad and still hot, well we proved:
The engine temp sensor is fine,
The loom too the ECU is fine
The fans work..
Under tray is removed so should help cooling
Your not going to like it...... ECU?
What happens if you plug an ECU from a pre-miniface lift in your tractor? Would it start? - can you get around the immobiliser problems?
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Only my 2 pennyworth......but it does sound a bit like it doesnt have enough pressure....temp will be hotter than the normal if not enough pressure....If you take the top off the coolant bottle when you have just stopped it and its still hot.....i would expect it to chuck hot water outa the bottle for a second....if you dont release the pressure gently.
Tho not enough pressure could be because of the hiss from the coolant bottle top....leaking the pressure.....are you sure that its a known good working top?
Is it the same as your MV6? ie could you swap them over to see what happens?
Its already had a replacement coolant bottle, bit of a bodge job as the V6 ones have extra pipes compared to the tractors.
Hummm new rad and still hot, well we proved:
The engine temp sensor is fine,
The loom too the ECU is fine
The fans work..
Under tray is removed so should help cooling
Your not going to like it...... ECU?
What happens if you plug an ECU from a pre-miniface lift in your tractor? Would it start? - can you get around the immobiliser problems?
ECU plays no part in cooling....
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Only my 2 pennyworth......but it does sound a bit like it doesnt have enough pressure....temp will be hotter than the normal if not enough pressure....If you take the top off the coolant bottle when you have just stopped it and its still hot.....i would expect it to chuck hot water outa the bottle for a second....if you dont release the pressure gently.
Tho not enough pressure could be because of the hiss from the coolant bottle top....leaking the pressure.....are you sure that its a known good working top?
Is it the same as your MV6? ie could you swap them over to see what happens?
Its not the cap from MV6 - that car is working and needs to stay that way. I have, however, tried 3 caps now....
Ok now ive looked the MV6 coolant bottle cap wont prove anything anyway......
The caps that you have tried.....are they definately the correct ones?
Ive found part numbers for petrol engine caps, U25TD, X25TD and Y25TD caps
So whats the difference? :-/ Different shapes....dont know....
Different pressure release valves?.....dont know
Just a thought....
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Tunnie and I proved yesterday that the old radiator had a problem. We poured boiling water in it, and the middle section remained cold. We poured all sorts of stuff in it to clear blockage, and got loads of crap out. Running a hose through it showed it could cope with the flow of hosepipe on full. However, upon refitting, same problems with the car running too warm, and losing its coolant out of the cap.
So I bought a new rad today, fitted, but, yes, you guessed it, the problem remains >:(
The car is fine when gently driving around, but as soon as you start booting it, the temperature goes up to 95/96 (on the dash gauge), at which point I lift off a bit. It pops the cap and loses a cupful or so of coolant. If I gently drive home/somewhere safe, the cap may be slightly hissing, but removing cap shows no real pressure.
The middle of the gauge is 95 degrees. Omegatoy tells me that they should run 90 - 92 degrees.
I know the viscous fan may be problematic - but does this have much affect at 80mph (surely airflow should be enough??). The ECU is putting in substitute values for coolant temp due to an issue with the sensor/wiring.
Cooling aside, the engine appears faultless.
So far, I have replaced waterpump, thermostat, cap, and radiator.
I really, really am after some ideas and inspiration now.
90 to 92 cruising mate booting it goes up to about 96 97 but it doesent loose coolant at all, and cools back down if i return to gentle throttle, you still got bubbles in the header tank? cos the only time i have come across something similar was when i had a car in that constantley threw its coolant out after booting it, afer much headscratching and searching i found he had mixed his antifreeze up with his windscreen washer fluid(both blue) and it ran fine till you booted it then it would throw water out!!! course when we completely drained the system (had to do it 3 times)and refilled it it stopped doing it!!
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Tunnie and I proved yesterday that the old radiator had a problem. We poured boiling water in it, and the middle section remained cold. We poured all sorts of stuff in it to clear blockage, and got loads of crap out. Running a hose through it showed it could cope with the flow of hosepipe on full. However, upon refitting, same problems with the car running too warm, and losing its coolant out of the cap.
So I bought a new rad today, fitted, but, yes, you guessed it, the problem remains >:(
The car is fine when gently driving around, but as soon as you start booting it, the temperature goes up to 95/96 (on the dash gauge), at which point I lift off a bit. It pops the cap and loses a cupful or so of coolant. If I gently drive home/somewhere safe, the cap may be slightly hissing, but removing cap shows no real pressure.
The middle of the gauge is 95 degrees. Omegatoy tells me that they should run 90 - 92 degrees.
I know the viscous fan may be problematic - but does this have much affect at 80mph (surely airflow should be enough??). The ECU is putting in substitute values for coolant temp due to an issue with the sensor/wiring.
Cooling aside, the engine appears faultless.
So far, I have replaced waterpump, thermostat, cap, and radiator.
I really, really am after some ideas and inspiration now.
90 to 92 cruising mate booting it goes up to about 96 97 but it doesent loose coolant at all, and cools back down if i return to gentle throttle, you still got bubbles in the header tank? cos the only time i have come across something similar was when i had a car in that constantley threw its coolant out after booting it, afer much headscratching and searching i found he had mixed his antifreeze up with his windscreen washer fluid(both blue) and it ran fine till you booted it then it would throw water out!!! course when we completely drained the system (had to do it 3 times)and refilled it it stopped doing it!!
Pretty sure Jaime has flushed the system many times...
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Tunnie and I proved yesterday that the old radiator had a problem. We poured boiling water in it, and the middle section remained cold. We poured all sorts of stuff in it to clear blockage, and got loads of crap out. Running a hose through it showed it could cope with the flow of hosepipe on full. However, upon refitting, same problems with the car running too warm, and losing its coolant out of the cap.
So I bought a new rad today, fitted, but, yes, you guessed it, the problem remains >:(
The car is fine when gently driving around, but as soon as you start booting it, the temperature goes up to 95/96 (on the dash gauge), at which point I lift off a bit. It pops the cap and loses a cupful or so of coolant. If I gently drive home/somewhere safe, the cap may be slightly hissing, but removing cap shows no real pressure.
The middle of the gauge is 95 degrees. Omegatoy tells me that they should run 90 - 92 degrees.
I know the viscous fan may be problematic - but does this have much affect at 80mph (surely airflow should be enough??). The ECU is putting in substitute values for coolant temp due to an issue with the sensor/wiring.
Cooling aside, the engine appears faultless.
So far, I have replaced waterpump, thermostat, cap, and radiator.
I really, really am after some ideas and inspiration now.
90 to 92 cruising mate booting it goes up to about 96 97 but it doesent loose coolant at all, and cools back down if i return to gentle throttle, you still got bubbles in the header tank? cos the only time i have come across something similar was when i had a car in that constantley threw its coolant out after booting it, afer much headscratching and searching i found he had mixed his antifreeze up with his windscreen washer fluid(both blue) and it ran fine till you booted it then it would throw water out!!! course when we completely drained the system (had to do it 3 times)and refilled it it stopped doing it!!
Mine seems to want to go up to 94 ish, maybe 95, easily. Boot it (fairly lightly and for only a short time), and it goes up and up. Don't like to see it above 96/97 so I back off, but it struggles to cool back down. :-/
I am completely out of ideas.
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90 to 92 cruising mate booting it goes up to about 96 97 but it doesent loose coolant at all, and cools back down if i return to gentle throttle, you still got bubbles in the header tank? cos the only time i have come across something similar was when i had a car in that constantley threw its coolant out after booting it, afer much headscratching and searching i found he had mixed his antifreeze up with his windscreen washer fluid(both blue) and it ran fine till you booted it then it would throw water out!!! course when we completely drained the system (had to do it 3 times)and refilled it it stopped doing it!!
And it has been flushed through several times ;)
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your not going to like this but i wonder if the thermostat you fitted could be to hot? cos i remember you saying you bridged the fans and dit made no difference?haqve you bridged the fans with the new rad fitted?
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your not going to like this but i wonder if the thermostat you fitted could be to hot? cos i remember you saying you bridged the fans and dit made no difference?haqve you bridged the fans with the new rad fitted?
I have not had fans on with new rad....
I have the Q&H part number for the stat if someone has the ability to cross reference?
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Tunnie and I proved yesterday that the old radiator had a problem. We poured boiling water in it, and the middle section remained cold. We poured all sorts of stuff in it to clear blockage, and got loads of crap out. Running a hose through it showed it could cope with the flow of hosepipe on full. However, upon refitting, same problems with the car running too warm, and losing its coolant out of the cap.
So I bought a new rad today, fitted, but, yes, you guessed it, the problem remains >:(
The car is fine when gently driving around, but as soon as you start booting it, the temperature goes up to 95/96 (on the dash gauge), at which point I lift off a bit. It pops the cap and loses a cupful or so of coolant. If I gently drive home/somewhere safe, the cap may be slightly hissing, but removing cap shows no real pressure.
The middle of the gauge is 95 degrees. Omegatoy tells me that they should run 90 - 92 degrees.
I know the viscous fan may be problematic - but does this have much affect at 80mph (surely airflow should be enough??). The ECU is putting in substitute values for coolant temp due to an issue with the sensor/wiring.
Cooling aside, the engine appears faultless.
So far, I have replaced waterpump, thermostat, cap, and radiator.
I really, really am after some ideas and inspiration now.
90 to 92 cruising mate booting it goes up to about 96 97 but it doesent loose coolant at all, and cools back down if i return to gentle throttle, you still got bubbles in the header tank? cos the only time i have come across something similar was when i had a car in that constantley threw its coolant out after booting it, afer much headscratching and searching i found he had mixed his antifreeze up with his windscreen washer fluid(both blue) and it ran fine till you booted it then it would throw water out!!! course when we completely drained the system (had to do it 3 times)and refilled it it stopped doing it!!
Mine seems to want to go up to 94 ish, maybe 95, easily. Boot it (fairly lightly and for only a short time), and it goes up and up. Don't like to see it above 96/97 so I back off, but it struggles to cool back down. :-/
I am completely out of ideas.
Rather than post up before thinking much about it, markie and I are going to have a chat about this tonight and see if we can pull any ideas together. I can't promise, but it can't hurt to try.
Initial questions though:
1) Have you done a compression test?
2) Have you put an exhaust sniffer in header tank? Needs to be eliminated.
3) Have you substituted the HBV for a known good one (I can bring one over if you don't have one)
4) When you give it a hard rev, does the temp drop at all, or just relentlessly keep rising?
5) Can the Tech2 talk to the CTS now it's been changed?
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1) Have you done a compression test?
2) Have you put an exhaust sniffer in header tank? Needs to be eliminated.
3) Have you substituted the HBV for a known good one (I can bring one over if you don't have one)
4) When you give it a hard rev, does the temp drop at all, or just relentlessly keep rising?
5) Can the Tech2 talk to the CTS now it's been changed?
1) No - I really, really don't think its HG. Omegatoy has seen it, perhaps he can comment on HG likelyhood?
2) No - as 1)
3) No. Not sure if its the same as V6. Certainly easier to get at, and is not leaking.
4) Revving it on the driveway doesn't heat it up much, needs to be under load to be honest, that means driving it.
5) CTS not changed, looks like wiring issue. M_DTM and I have just been going through the wiring diagrams. This needs to be resolved, but I'm not convinced this is the issue. M_DTM is less convinced though.
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I agree that HG is unlikely.. but for the sake of getting a 5 min test done, it would be something you could definitively tick off the list...
This is one of those pain in the ass problems.....
Which will turn out to have a stupidly simple solution...
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1) Have you done a compression test?
2) Have you put an exhaust sniffer in header tank? Needs to be eliminated.
3) Have you substituted the HBV for a known good one (I can bring one over if you don't have one)
4) When you give it a hard rev, does the temp drop at all, or just relentlessly keep rising?
5) Can the Tech2 talk to the CTS now it's been changed?
1) No - I really, really don't think its HG. Omegatoy has seen it, perhaps he can comment on HG likelyhood?
2) No - as 1)
3) No. Not sure if its the same as V6. Certainly easier to get at, and is not leaking.
4) Revving it on the driveway doesn't heat it up much, needs to be under load to be honest, that means driving it.
5) CTS not changed, looks like wiring issue. M_DTM and I have just been going through the wiring diagrams. This needs to be resolved, but I'm not convinced this is the issue. M_DTM is less convinced though.
I dont hink its head gasket at all, diesels rely on compression to fire the mixture and if you had a gasket gone it just wouldnt fire up so sweet even when its chucked out its coolant it still fires up sweetly, i reckon it could be the thermostat or a blockage somewhere in the system
Omegatoy
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Which will turn out to have a stupidly simple solution...
I hope so....
I don't feel too bad about the rad, as Tunnie and I proved an issue with old one, though I thought I'd helped with all the rad flushing we did.... >:(
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1) Have you done a compression test?
2) Have you put an exhaust sniffer in header tank? Needs to be eliminated.
3) Have you substituted the HBV for a known good one (I can bring one over if you don't have one)
4) When you give it a hard rev, does the temp drop at all, or just relentlessly keep rising?
5) Can the Tech2 talk to the CTS now it's been changed?
1) No - I really, really don't think its HG. Omegatoy has seen it, perhaps he can comment on HG likelyhood?
2) No - as 1)
3) No. Not sure if its the same as V6. Certainly easier to get at, and is not leaking.
4) Revving it on the driveway doesn't heat it up much, needs to be under load to be honest, that means driving it.
5) CTS not changed, looks like wiring issue. M_DTM and I have just been going through the wiring diagrams. This needs to be resolved, but I'm not convinced this is the issue. M_DTM is less convinced though.
I dont hink its head gasket at all, diesels rely on compression to fire the mixture and if you had a gasket gone it just wouldnt fire up so sweet even when its chucked out its coolant it still fires up sweetly, i reckon it could be the thermostat or a blockage somewhere in the system
Omegatoy
I totally agree mate, but.. as said... for the sake of a 5 min test... it would be something you could 100% tick off the list of suspects...
I had a Pug 405 diesel 1.9, admittedly a totally different engine... but it had a HG issue causing the cap to push out coolant, yet it ran sweet as sugar...
I DO agree it's not likely, but I also think proving exhaust gas is not present in the cooling system is a quick (hence very worthwhile) test to do :)
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I dont hink its head gasket at all, diesels rely on compression to fire the mixture and if you had a gasket gone it just wouldnt fire up so sweet even when its chucked out its coolant it still fires up sweetly, i reckon it could be the thermostat or a blockage somewhere in the system
Omegatoy
Exactly my understanding as well. I have seen a diesel HG failure, and believe me, you know about it ;)
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Depends on the type of car
See my post above, about Pug TD HG failure
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Depends on the type of car
See my post above, about Pug TD HG failure
Running aside, if it was (over) pressurising the coolant, there would be bubbles in coolant. Lots of bubbles.
As stated, the engine seems perfect until you start putting under load...
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Depends on the type of car
See my post above, about Pug TD HG failure
Running aside, if it was (over) pressurising the coolant, there would be bubbles in coolant. Lots of bubbles.
As stated, the engine seems perfect until you start putting under load...
This is going to be an interesting one, whatever the outcome
I agree with everything said, about it's unlikely HG... but the one thing I've learned, is never take anything for granted on Omega's :(
You must be feeling a bit down about it... I know I did, when my old 2.0GLS project refused to start whatever I did.. you start to loose all faith in the car..
But please don't - you will get there.
If at first you don't suceed...
This is only a thought... but I wonder if someone put radweld in it at some point to try and cure a small leak?
I once, (long time ago, I've learned a lot since!) stupidly put Radweld in an Omega V6... in short, it ruined the engine.. constantly over-pressuring, running too hot, blowing from the cap etc... I can only imagine it clogged up the tiny waterways..
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What was the old water pump like when you changed it? any bits missing from the blades?
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What was the old water pump like when you changed it? any bits missing from the blades?
Old waterpump was good.
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This is only a thought... but I wonder if someone put radweld in it at some point to try and cure a small leak?
I once, (long time ago, I've learned a lot since!) stupidly put Radweld in an Omega V6... in short, it ruined the engine.. constantly over-pressuring, running too hot, blowing from the cap etc... I can only imagine it clogged up the tiny waterways..
Yes, previous owner put some of that HG repair stuff in - lots of copper particles in the coolant (hardly any now due to flushing.
However, will they be any narrow waterways in engine?
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i still say put bleach in the coolant system.... with water. Then take it for a damn good thrashing, flush though with water and repeat again.
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Something is blocking water flow, pump could be cavitating.
Airlocks, blockages, duff pump, thermostat.
Can you try with thermostat removed and see if that fixes the boiling?
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Something is blocking water flow, pump could be cavitating.
Airlocks, blockages, duff pump, thermostat.
Can you try with thermostat removed and see if that fixes the boiling?
He's changed pump, and stat..
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This is only a thought... but I wonder if someone put radweld in it at some point to try and cure a small leak?
I once, (long time ago, I've learned a lot since!) stupidly put Radweld in an Omega V6... in short, it ruined the engine.. constantly over-pressuring, running too hot, blowing from the cap etc... I can only imagine it clogged up the tiny waterways..
Yes, previous owner put some of that HG repair stuff in - lots of copper particles in the coolant (hardly any now due to flushing.
However, will they be any narrow waterways in engine?
Ahh.. interesting...significant news...
I'll bet you a few beers in a brackley pub, it's related to the tack they've put in the engine then
Like I say.. a few years back... I killed a V6 Omega with radweld..
As a result.. I never touch the stuff.. I think it should be banned... ;D
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I think, for what it's worth, you must have a blockage somewhere in the water channels.
With all the gunge the previous owner put in the system, this can't have helped.
I don't know about finding it though, without stripping the head.
My monies defo. on a blockage in the engine channels.
You've tried everything else, except change all the hoses.
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I think, for what it's worth, you must have a blockage somewhere in the water channels.
I don't know about finding it though, without stripping the head.
My monies defo. on a blockage in the engine channels.
The only thing you could attempt, without dismantling, is some kind of mega strong flushing agent!! I read something over the other side once about the "pope" method.. and I've heard of people filling their coolant systems with petrol (from cold!) and running for a very short time... not sure I'd want to try it though!!!
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I think, for what it's worth, you must have a blockage somewhere in the water channels.
I don't know about finding it though, without stripping the head.
My monies defo. on a blockage in the engine channels.
The only thing you could attempt, without dismantling, is some kind of mega strong flushing agent!! I read something over the other side once about the "pope" method.. and I've heard of people filling their coolant systems with petrol (from cold!) and running for a very short time... not sure I'd want to try it though!!!
Also, Jamie, have you flushed that heater matrix yet? Regardless of the heat in the cabin, they can gunge up and restrict coolant flow - on some cars it has more of an affect than others. (Eg rovers don't seem to mind it - but Omegas (V6's anyway) run very hot with matrix a bit blocked)
I know it's a knuckle scraping job... but flush it from the top first, until it runs clear at the bottom... let the hose run for a good length of time... and then reverse flush from the bottom... you should see more crap coloured stuff come out when reverse flushing.....
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I think, for what it's worth, you must have a blockage somewhere in the water channels.
I don't know about finding it though, without stripping the head.
My monies defo. on a blockage in the engine channels.
The only thing you could attempt, without dismantling, is some kind of mega strong flushing agent!! I read something over the other side once about the "pope" method.. and I've heard of people filling their coolant systems with petrol (from cold!) and running for a very short time... not sure I'd want to try it though!!!
Also, Jamie, have you flushed that heater matrix yet? Regardless of the heat in the cabin, they can gunge up and restrict coolant flow - on some cars it has more of an affect than others. (Eg rovers don't seem to mind it - but Omegas (V6's anyway) run very hot with matrix a bit blocked)
I know it's a knuckle scraping job... but flush it from the top first, until it runs clear at the bottom... let the hose run for a good length of time... and then reverse flush from the bottom... you should see more crap coloured stuff come out when reverse flushing.....
But if it was the heater matrix blocked, then the engine would cool when the coolant flow to matrix is stopped by hbv when set to cold. Also, heater matrix doesn't appear to be in main coolant flow.
There is a large hose from the head to the top of rad. There is another large hose from the bottom of rad to back to stat on the block, so should be a good flow from block, around engine via pump to head, to top rad hose, through rad, back to stat.
The original stat had holes drill in it, in effect bypassing it.
Is it possible to put the stat in wrong way round - would it fit, and would it affect it? I put stat in same way round as old one came out, though possible that was wrong??
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I think, for what it's worth, you must have a blockage somewhere in the water channels.
I don't know about finding it though, without stripping the head.
My monies defo. on a blockage in the engine channels.
The only thing you could attempt, without dismantling, is some kind of mega strong flushing agent!! I read something over the other side once about the "pope" method.. and I've heard of people filling their coolant systems with petrol (from cold!) and running for a very short time... not sure I'd want to try it though!!!
Also, Jamie, have you flushed that heater matrix yet? Regardless of the heat in the cabin, they can gunge up and restrict coolant flow - on some cars it has more of an affect than others. (Eg rovers don't seem to mind it - but Omegas (V6's anyway) run very hot with matrix a bit blocked)
I know it's a knuckle scraping job... but flush it from the top first, until it runs clear at the bottom... let the hose run for a good length of time... and then reverse flush from the bottom... you should see more crap coloured stuff come out when reverse flushing.....
But if it was the heater matrix blocked, then the engine would cool when the coolant flow to matrix is stopped by hbv when set to cold. Also, heater matrix doesn't appear to be in main coolant flow.
There is a large hose from the head to the top of rad. There is another large hose from the bottom of rad to back to stat on the block, so should be a good flow from block, around engine via pump to head, to top rad hose, through rad, back to stat.
The original stat had holes drill in it, in effect bypassing it.
Is it possible to put the stat in wrong way round - would it fit, and would it affect it? I put stat in same way round as old one came out, though possible that was wrong??
I know that you can put the stat in the wrong way on some cars, not sure about the Omega.
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Thinking about the stat, and coolant flow. I am wondering if the stat is fitted wrong way round...
It was fitted the same way round as old one. Normally, they are fitted so the stat points towards the rad I believe?
However, this engine, the stat appears to be on the water inlet (?) from the bottom of the rad, rather than the normal outlet to the top of the rad?
Can anyone definatively tell me which way round it should go?
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Thinking about the stat, and coolant flow. I am wondering if the stat is fitted wrong way round...
It was fitted the same way round as old one. Normally, they are fitted so the stat points towards the rad I believe?
However, this engine, the stat appears to be on the water inlet (?) from the bottom of the rad, rather than the normal outlet to the top of the rad?
Can anyone definatively tell me which way round it should go?
Is it difficult to swop around? You've got nothing to lose by trying it the other way.
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Thinking about the stat, and coolant flow. I am wondering if the stat is fitted wrong way round...
It was fitted the same way round as old one. Normally, they are fitted so the stat points towards the rad I believe?
However, this engine, the stat appears to be on the water inlet (?) from the bottom of the rad, rather than the normal outlet to the top of the rad?
Can anyone definatively tell me which way round it should go?
Is it difficult to swop around? You've got nothing to lose by trying it the other way.
A damn sight easier than v6 one ;)
But I want to ensure it goes in the right way....
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Looked up the stat they sold me, QH part QTH353, and it is the right part. Quite a cold stat at 80 degrees.
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I may have missed this earlier in the discussion, but I have a vague memory of BMW coolant pumps having plastic impellors prone to failure. It is a BMW 6 ?
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I may have missed this earlier in the discussion, but I have a vague memory of BMW coolant pumps having plastic impellors prone to failure. It is a BMW 6 ?
Yes it has, but pump already changed (nothing wrong with old one). My first thoughts were pump as well, but Auto Addict and I changed that a couple of weeks ago.
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Normally the side of a thermostat that faces the "hot" side of the cooling system is the side with the spring. I think this is the case whether it's in the flow or return radiator hose.
I would expect an engine to need to get up to 110-120 degrees before it blows the cap. The fact that it's doing it at such a low indicated temperature suggests one of the following:
1) Pressurisation is due to ingested air through HBV leak, etc. or head gasket, not boiling coolant.
2) The gauge is lying and the engine is getting hotter than it says.
3) Coolant flow is restricted causing boiling in some parts of the system while the overall temperature remains OK.
4) The cap opening pressure is too low.
5) The coolant antifreeze concentration is low.
I think most of the above have been eliminated. I'm starting to wonder about that additive in the coolant. If this is caked on somewhere it could be causing localised boiling. I read somewhere about flusing the cooling system with a degreaser such as Jizer or Gunk. Maybe more appropriate to cleaning out old oil after an oil cooler rupture but I'm wondering what would be best to shift whatever has contaminated this system?
Kevin
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Not cheap but, supposed to be very good.....
http://cgi.ebay.co.uk/FORTE-Cooling-System-Flush_W0QQitemZ330077166914QQihZ014QQcategoryZ25632QQrdZ1QQssPageNameZWD1VQQcmdZViewItem
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I suggested no stat to see if it boiled without it.
I think some strong degunger is required, possibly even head off and flush out the head waterways, this is the hottest part and most likely to be the boiling.
Can't find anything on the internet about the M51 overheating, just comments about BMW engines of that era getting clogged by broken off plastic water pump blades.
Can you tell which direction the water flow is?
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OK, double checked stat. Spring faces engine, same as shown in TIS, and same as M_DTM's advice.
It has been idling on the drive now for about an hour, and is running at 92. Top corner of rad is hot (where pipe from top of engine meets rad), rest of rad is cold, slowly warming up from that corner. How quickly should the rad heat up once stat supposedly open?
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Just a suggestion but could a partially blocked heater matrix cause these problems :-/
You say water is running through fine but could it be corroded enough to cause heating issues.
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Just a suggestion but could a partially blocked heater matrix cause these problems :-/
You say water is running through fine but could it be corroded enough to cause heating issues.
The heater will be bypassed via hbv if heating set to cold.
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OK, stopped the engine. Dash gauge around 93 degrees.
Top hose hot. Bottom hose from rad to stat is cold.
Either:
1) I have the worlds most effective rad
2) I have no circulation at all (or minimal) through rad - would the engine heating up cause the water to expand enough to get the hot water in top hose, possible a bit in the rad?
Can an expert say what will happen if I remove stat completely - could my new stat be faulty (and the original stat OK-ish, albeit drilled)?
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Just a suggestion but could a partially blocked heater matrix cause these problems :-/
You say water is running through fine but could it be corroded enough to cause heating issues.
The heater will be bypassed via hbv if heating set to cold.
Ok, never thought of that :y
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OK, double checked stat. Spring faces engine, same as shown in TIS, and same as M_DTM's advice.
It has been idling on the drive now for about an hour, and is running at 92. Top corner of rad is hot (where pipe from top of engine meets rad), rest of rad is cold, slowly warming up from that corner. How quickly should the rad heat up once stat supposedly open?
Just double check the design of the thermostat, the wax capsule should face the heat source (engine) Im fairly certain there are designs with the spring on the opposite side to the capsule.
Im surprised that its only just opening the stat after an hour, seems a bit slow to warm up but then Im not familiar with diseasels.
Is there a vent in the thermostat plate or some other way that air can be purged from the stat?, they only work if 'wet', should clear any trapped air once it does open though.
How much sludge or muck have you seen in hoses, around the pump cavity etc? The waterways in an engine are fairly large so wouldnt tend to block up, radiators have much smaller passageways so clog up first and you think your old radiator was OK.
Does a diesel run hotter if injection is late (retarded), certainly makes petrol run very hot?
The old pump was OK....could it have been changed following an impellor failure and the bits are still in the water ways? I ask because it seems a common thread if you search for cooling probs on 5 series.
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I have a thermocouple type temp meter somewhere, we can slip the thermocouple under a hose joint to confirm the real water temp. This would confirm the gauge reading.
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Does a diesel run hotter if injection is late (retarded), certainly makes petrol run very hot?
Apparantly yes, this is a technique used during warm up to get them upto temp quicker...not sure if this power plant uses this technique though...
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It is minimal circulation.
Try with no stat and see what happens.
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OK, double checked stat. Spring faces engine, same as shown in TIS, and same as M_DTM's advice.
It has been idling on the drive now for about an hour, and is running at 92. Top corner of rad is hot (where pipe from top of engine meets rad), rest of rad is cold, slowly warming up from that corner. How quickly should the rad heat up once stat supposedly open?
Just double check the design of the thermostat, the wax capsule should face the heat source (engine) Im fairly certain there are designs with the spring on the opposite side to the capsule.
Im surprised that its only just opening the stat after an hour, seems a bit slow to warm up but then Im not familiar with diseasels.
Is there a vent in the thermostat plate or some other way that air can be purged from the stat?, they only work if 'wet', should clear any trapped air once it does open though.
How much sludge or muck have you seen in hoses, around the pump cavity etc? The waterways in an engine are fairly large so wouldnt tend to block up, radiators have much smaller passageways so clog up first and you think your old radiator was OK.
Does a diesel run hotter if injection is late (retarded), certainly makes petrol run very hot?
The old pump was OK....could it have been changed following an impellor failure and the bits are still in the water ways? I ask because it seems a common thread if you search for cooling probs on 5 series.
Sorry, it reached 90ish after about 10mins, maybe 15m. After an hour, it was still 92. Sorry if I was unclear....
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How much sludge or muck have you seen in hoses, around the pump cavity etc? The waterways in an engine are fairly large so wouldnt tend to block up, radiators have much smaller passageways so clog up first and you think your old radiator was OK.
We found the old rad had a cold spot. Also, it had signs of a repair. So I have put on a spanking new GM rad.
The hoses I've had off look nice a clear, just discoloured (brown) inside. No gunge.
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Just double check the design of the thermostat, the wax capsule should face the heat source (engine) Im fairly certain there are designs with the spring on the opposite side to the capsule.
New stat:
(http://images.omegaowners.com/images/theboy/project_tb2/newstat.jpg)
Old stat:
(http://images.omegaowners.com/images/theboy/project_tb2/oldstat.jpg)
Both were fitted with spring towards engine. It seems to me to be on the water inlet (comes from bottom rad hose).
?
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Looks like the spring side of both of them is the capsule side so spring side towards engine is correct.
Sounds like it's a similar setup to the Rover K series where the thermostat is in the return from the rad. Bypass flow past the bottom of the 'stat is very important in this type of setup because the water from the radiator will be continually cooling the 'stat. Is it possible to see how the 'stat gets bypass flow (is it in a separate housing?) Could it be it comes from the HBV and it's blocked?
It would be interesting to run it without a stat in, just to see what happens.
Kevin
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.... if it's easy-ish to ge at, why not turn the stat around anyway and see if that helps?
... and the "pope" method is to use gunk to flush with followed by a couple more normal ones afterwards. Not sure how any rubber seals might take that treatment though!
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Going to attempt to run without stat as soon as I can work out how to get a seal (seal is normally on the stat). Might just drill some more holes in old stat....
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Just been for a spin with the drilled stat in, and the visco fan off.
Unfortunately, due to caravanners and old people, I couldn't really give it too much of a bootful. Its the hardest I've driven it since I got it, and it stayed 93 - 95 through most of it, creeping up to 96 after giving it a bootload, then following grandad in his Audi at 15mph through town.
Still lost a load of coolant out of the cap though.
Any more ideas?
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Possible, with the other problems, I've damaged all 3 caps? I am reluctant to try MV6 cap, as that needs to get me to Drax tomorrow ::)
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Just a wild idea / long shot / stab in the dark etc. - and probably wrong - but is there a hose that is collapsing when hot? This would either severely reduce or even stop the flow of coolant. It would also increase the pressure................ Are any hoses pinched in some way i.e. caught between ancillaries / engine components etc?
It is possible I suppose that the 3 caps are damaged in some way due to excess pressure but somehow I doubt it.
Finally, sorry if the above is plain stupid but it is all I can think of!
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Just a wild idea / long shot / stab in the dark etc. - and probably wrong - but is there a hose that is collapsing when hot? This would either severely reduce or even stop the flow of coolant. It would also increase the pressure................ Are any hoses pinched in some way i.e. caught between ancillaries / engine components etc?
It is possible I suppose that the 3 caps are damaged in some way due to excess pressure but somehow I doubt it.
Finally, sorry if the above is plain stupid but it is all I can think of!
All posts gratefully received, read, and considered :y :y
The coolant system on the tractor appears to be around the engine, 1 think hose from head to rad, the rad, 1 think hose from rad to stat, stat to engine (obviously the pump somewhere in the block as well).
So only 2 hoses are the 2 big ones from to/from rad. They do look absolutely fine though.
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OK
Another thought - you have replaced the original expansion tank with one from a V6. A further long shot - I wonder is the design pressure for the expansion cap is too low? If it is this would explain the cap blowing off and loosing water. It would also explain the overheating as, when the pressure is released by the cap, the boiling point of the coolant is reduced.
As I say, another long shot, but worth considering.
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OK
I wonder is the design pressure for the expansion cap is too low?
Often the pressure is stamped into the cap itself.
Kevin
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OK
Another thought - you have replaced the original expansion tank with one from a V6. A further long shot - I wonder is the design pressure for the expansion cap is too low? If it is this would explain the cap blowing off and loosing water. It would also explain the overheating as, when the pressure is released by the cap, the boiling point of the coolant is reduced.
As I say, another long shot, but worth considering.
Its running a v6 expansion tank, as the diesel one suffers the same symptoms...
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Just a wild idea / long shot / stab in the dark etc. - and probably wrong - but is there a hose that is collapsing when hot? This would either severely reduce or even stop the flow of coolant. It would also increase the pressure................ Are any hoses pinched in some way i.e. caught between ancillaries / engine components etc?
It is possible I suppose that the 3 caps are damaged in some way due to excess pressure but somehow I doubt it.
Finally, sorry if the above is plain stupid but it is all I can think of!
Its not stupid, I had a car where the hose collapsed internally (they are made of two layers of rubber sandwiching a fabric layer) from outside it looked OK but the bore was almost completely blocked by the inner layer which had separated from the fabric part.
Only clue was that it felt very soft to squeeze.
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Right then, went to Towcester to go shopping, about 10 miles away, all dual carriageway, kept it at constant 70mph. Bear in mind I currently have the drilled stat in. Stayed below 90 degrees most of the way, couple of times did go up to 92ish. On arrival at Tescos, I had lost probably 1l of coolant, nicely sprayed around suspension strut and airbox.
So we did our shopping, and I then filled the coolant back up, and put on the cap that Omegatoy got from the diesel in the scrappy. Drove back, constant 70mph, temperatures same as before, mainly near the end stop, but occasionally rising up to 92ish. However, upon arriving home, the cap was hissing (this cap even hisses when you drain coolant, but forget to remove cap, so I had written it off as knackered), but had lost minimal coolant. Undoing the cap slightly, and it did exactly what I would expect a hot car to do - hiss voilently, and start to boil in the bottle. Radiator was hot all over - too hot to hold for too long.
Feeling like a better test was needed, I wired up the leccy fans (and the intercooler fan) and took it for a decent thrashing, only to be prevented from doing so by today's ridiculously slow drivers. Opened it up when I could. Temp was around 90 - 92, dropping back down to endstop whislt following grandma and grandad. Again hissing, but minimal coolant loss (though defo still some)....
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I was nowhere near you today..... :-?
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I was nowhere near you today..... :-?
Not you AA - you drive at 45 everywhere. These idiots were crawling. I could have pushed the car faster!
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Right then, went to Towcester to go shopping, about 10 miles away, all dual carriageway, kept it at constant 70mph. Bear in mind I currently have the drilled stat in. Stayed below 90 degrees most of the way, couple of times did go up to 92ish. On arrival at Tescos, I had lost probably 1l of coolant, nicely sprayed around suspension strut and airbox.
So we did our shopping, and I then filled the coolant back up, and put on the cap that Omegatoy got from the diesel in the scrappy. Drove back, constant 70mph, temperatures same as before, mainly near the end stop, but occasionally rising up to 92ish. However, upon arriving home, the cap was hissing (this cap even hisses when you drain coolant, but forget to remove cap, so I had written it off as knackered), but had lost minimal coolant. Undoing the cap slightly, and it did exactly what I would expect a hot car to do - hiss voilently, and start to boil in the bottle. Radiator was hot all over - too hot to hold for too long.
Feeling like a better test was needed, I wired up the leccy fans (and the intercooler fan) and took it for a decent thrashing, only to be prevented from doing so by today's ridiculously slow drivers. Opened it up when I could. Temp was around 90 - 92, dropping back down to endstop whislt following grandma and grandad. Again hissing, but minimal coolant loss (though defo still some)....
Hmmm thats interesting, with a lot of holes drilled you effectively have permanent flow ignoring the bypass system, wonder if the new stat is faulty? the answer is here somewhere just cant get it out in the open yet!!!!
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Right then, went to Towcester to go shopping, about 10 miles away, all dual carriageway, kept it at constant 70mph. Bear in mind I currently have the drilled stat in. Stayed below 90 degrees most of the way, couple of times did go up to 92ish. On arrival at Tescos, I had lost probably 1l of coolant, nicely sprayed around suspension strut and airbox.
So we did our shopping, and I then filled the coolant back up, and put on the cap that Omegatoy got from the diesel in the scrappy. Drove back, constant 70mph, temperatures same as before, mainly near the end stop, but occasionally rising up to 92ish. However, upon arriving home, the cap was hissing (this cap even hisses when you drain coolant, but forget to remove cap, so I had written it off as knackered), but had lost minimal coolant. Undoing the cap slightly, and it did exactly what I would expect a hot car to do - hiss voilently, and start to boil in the bottle. Radiator was hot all over - too hot to hold for too long.
Feeling like a better test was needed, I wired up the leccy fans (and the intercooler fan) and took it for a decent thrashing, only to be prevented from doing so by today's ridiculously slow drivers. Opened it up when I could. Temp was around 90 - 92, dropping back down to endstop whislt following grandma and grandad. Again hissing, but minimal coolant loss (though defo still some)....
Hmmm thats interesting, with a lot of holes drilled you effectively have permanent flow ignoring the bypass system, wonder if the new stat is faulty? the answer is here somewhere just cant get it out in the open yet!!!!
My current theory is all my caps are faulty....
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Why not run it without a thermostat?
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I suppose its possible that they were all exploded with teh original blocked radiator/ seems strange that you loose minimal coolant with the diesel one tho in spite of its hissing all the time?
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I suppose its possible that they were all exploded with teh original blocked radiator/ seems strange that you loose minimal coolant with the diesel one tho in spite of its hissing all the time?
I had written the diesel one off as faulty, as it even hisses when you undo the rad drain screw with the cap left on... :-/
But it does seem to be the best cap :-/
Maybe you could try my cap(s) and see what you get?
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I suppose its possible that they were all exploded with teh original blocked radiator/ seems strange that you loose minimal coolant with the diesel one tho in spite of its hissing all the time?
I had written the diesel one off as faulty, as it even hisses when you undo the rad drain screw with the cap left on... :-/
But it does seem to be the best cap :-/
Maybe you could try my cap(s) and see what you get?
would rather you tried mine!! i have new antifreeze in and dont want to lose it!!! give you a text when i get home tomorrow as i have a short day!!!!
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I suppose its possible that they were all exploded with teh original blocked radiator/ seems strange that you loose minimal coolant with the diesel one tho in spite of its hissing all the time?
I had written the diesel one off as faulty, as it even hisses when you undo the rad drain screw with the cap left on... :-/
But it does seem to be the best cap :-/
Maybe you could try my cap(s) and see what you get?
would rather you tried mine!! i have new antifreeze in and dont want to lose it!!! give you a text when i get home tomorrow as i have a short day!!!!
Tomorrow is the one day I am not around (Up at Drax). Any other day any good?
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Drat!! forgot about that trip, maybe friday? as i wont be around at teh weekend as will be gving the v6 a hard time at the trackday meet!!!
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Drat!! forgot about that trip, maybe friday? as i wont be around at teh weekend as will be gving the v6 a hard time at the trackday meet!!!
Not sure what time I'll be home, I could drop you a text?
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Interestingly, Quinton Hazell don't list a cap for 2.5TD in their online catalogue, on 2.0/2.5/3.0 :-?
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Drat!! forgot about that trip, maybe friday? as i wont be around at teh weekend as will be gving the v6 a hard time at the trackday meet!!!
Not sure what time I'll be home, I could drop you a text?
If your popping around to Brackley, can i sneak the Senny in too? ;)
I hope to have the replacement aux belt by then, although it will be the non air-con belt >:(
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Interestingly, Quinton Hazell don't list a cap for 2.5TD in their online catalogue, on 2.0/2.5/3.0 :-?
Think i mentioned in an earlier post about having the correct cap....EPC lists 4 types, one for petrols and 3 different one for diesels.
For the cost of one, they carnt be that much.....I'd suggest getting a new correct cap from vx dealer and trying that.....then you can discount it or even better it might solve it :y
Or
And maybe a correct coolant bottle while your about it :-/ (does a new coolant bottle come with the cap? :-/ )
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Have you sorted the known problem out yet.....the coolant sensor......its important when fault finding to minimise changes and fix known problems first....
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Had that problem on my 2.5TD a couple of years ago, it kept going into limp mode, ended up being the water pump after me shelling out about £380 for new radiator that i didnt need! >:(
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Taxi Driver, I don't think that new bottles come with the cap. It is silly not to provide a new cap I think.
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Have you sorted the known problem out yet.....the coolant sensor......its important when fault finding to minimise changes and fix known problems first....
No, thats this afternoons mission. As you know, whilst I accept it may create more heat, I am not convinced that this is the issue.
Though you are, of course, correct, and I will have a look at fixing the sensor issue.
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Saga contines at:
http://www.omegaowners.com/forum/YaBB.pl?num=1176495921