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[philsteward]

Hi all,

Just in the process of refitting my head after the gasket went between coolant and cylinder.  When I got it skimmed, they said it was warped by seven thousand of an inch, apparently 3 to 4 thousand is enough.  I asked him why it might have gone and he said only likely reason as everything else looked fine, was that it had overheated.  I have had the car 18months, and I knew the previous owner as a friend he had had it for 4 years and bought it when only 40k miles, it has never overheated.

My only thought is that I have noticed after a decent run, when you turn the engine off, if you put the ignition back on, you will see the temp gauge rise and rise all the way up above 100c.  This happening time after time has eventually knackered the head gasket and warped the head.

If I am correct, it is only the 2.2 engine which does not have the recirculate coolant pump for when the engine is turned off?  I do not mean the one to make the heater stay hot, just the one to circulate the coolant round the engine, all the v6s have them, and it seems that only the 2.2 is known for having head gasket issues.

My thoughts are to stop this happening again, is it possible to retrofit the inline pump the v6 models have?  How would I wire it in as it would only need to run when the engine is off, and the coolant temp is too high? Thought I could take the feed direct from the power feed for the coolant fan, that way if the water in the rad is too hot the fan would be on and turn the pump on, thus circulating the water, but would have thought it would need a delay relay so it stays on a bit after to try and reduce hot spots in the engine.

Hope that all makes sense, look forward to the flood of replies!!

Cheers

[henryd]

I don't think all of the V6 engines have that pump,something to do with a winter pack I think,may be wrong so someone who knows better will be along soon

[Andy B]

I don't think all of the V6 engines have that pump,something to do with a winter pack I think,may be wrong so someone who knows better will be along soon

Different pump Henry  It's the pump that opeldåre has just changed clicky that's part oof the winter pack. All V6s have the recirc pump on the main radiator 

[henryd]

I don't think all of the V6 engines have that pump,something to do with a winter pack I think,may be wrong so someone who knows better will be along soon

Different pump Henry  It's the pump that opeldåre has just changed clicky that's part oof the winter pack. All V6s have the recirc pump on the main radiator 

Fairynough ,don't ever recall seeing one on mine though

[Andy B]

....
Fairynough ,don't ever recall seeing one on mine though

Passenger side, at the top. It's the same pump as the winter pump too. 

[05omegav6]

Fans run on for a while after shut down if the temp is still high , so connecting the pump to the fan might be a runner

[Johnny English]

Hi all,

Just in the process of refitting my head after the gasket went between coolant and cylinder.  When I got it skimmed, they said it was warped by seven thousand of an inch, apparently 3 to 4 thousand is enough.  I asked him why it might have gone and he said only likely reason as everything else looked fine, was that it had overheated.  I have had the car 18months, and I knew the previous owner as a friend he had had it for 4 years and bought it when only 40k miles, it has never overheated.

My only thought is that I have noticed after a decent run, when you turn the engine off, if you put the ignition back on, you will see the temp gauge rise and rise all the way up above 100c.  This happening time after time has eventually knackered the head gasket and warped the head.

If I am correct, it is only the 2.2 engine which does not have the recirculate coolant pump for when the engine is turned off?  I do not mean the one to make the heater stay hot, just the one to circulate the coolant round the engine, all the v6s have them, and it seems that only the 2.2 is known for having head gasket issues.

My thoughts are to stop this happening again, is it possible to retrofit the inline pump the v6 models have?  How would I wire it in as it would only need to run when the engine is off, and the coolant temp is too high? Thought I could take the feed direct from the power feed for the coolant fan, that way if the water in the rad is too hot the fan would be on and turn the pump on, thus circulating the water, but would have thought it would need a delay relay so it stays on a bit after to try and reduce hot spots in the engine.

Hope that all makes sense, look forward to the flood of replies!!

Cheers

I would get it relayed rather and check the fuse value ! The fuse might be strong enough for a fan only but it is not sure in case of fan and pump at the same time ! Also be careful with the diameter of wires before doing anything. Possibly will be enough but I would measure the current of fan and pump together just in case. 

[philsteward]

Fans run on for a while after shut down if the temp is still high , so connecting the pump to the fan might be a runner

Am I correct that the fans run on assuming the sensor in the radiator is telling them to?  If that is the case, the coolant in the radiator might be cool enough, so fans don't come on, but the coolant in the engine could still be hot, so running direct off the fan wires might not work so well?

My thoughts are to stop this happening again, is it possible to retrofit the inline pump the v6 models have?  How would I wire it in as it would only need to run when the engine is off, and the coolant temp is too high? Thought I could take the feed direct from the power feed for the coolant fan, that way if the water in the rad is too hot the fan would be on and turn the pump on, thus circulating the water, but would have thought it would need a delay relay so it stays on a bit after to try and reduce hot spots in the engine.

I would get it relayed rather and check the fuse value ! The fuse might be strong enough for a fan only but it is not sure in case of fan and pump at the same time ! Also be careful with the diameter of wires before doing anything. Possibly will be enough but I would measure the current of fan and pump together just in case. 

Good thoughts, might be easier to just have it remote switched using the fan wires, on a delayed relay.  However that said, if the rad coolant is cool enough just at the time I switch the engine off, the pump still wouldn't come on!

Anyone any idea how the wiring works for the v6 fitted pumps?

Cheers for all the suggestions so far!

[Johnny English]

PM sent Phil.

[Kevin Wood]

My feeling on this is that, if there is a problem, the manufacturer would have fitted an aux. coolant pump on the 2.2.

Most engines will see a little rise in the water temperature after stopping the engine. This is simply residual heat in the block and head still being transferred into the coolant but, since the coolant isn't being recirculated, the small amount of coolant inside the engine gets a little warmer. It starts to circulate very slowly due to the thermosyphon effect and the first thing it hits after leaving the engine is the temperature sensor, hence the gauge increases.

During this process the head is simply cooling down from the temperature it was at when the engine was running. Just because the coolant temperature indication has risen, it doesn't mean the head has been cooked. The cylinder head gets much hotter than the coolant when the engine is running, and it has to get much hotter still before it is in danger of warping.

I think auxiliary pumps as fitted to the V6 are only fitted where there is a danger of "after-boiling", where the engine is large enough to hold sufficient heat to boil the coolant before the heat has dissipated naturally. Even then, it's probably only an issue in the warmer climates where the car is sold.

The V6 aux. pump also only really circulates the coolant around the radiator. I doubt much passes through the engine.

In short, I don't think the lack of such a pump has got anything to do with your warped head.

[philsteward]

My feeling on this is that, if there is a problem, the manufacturer would have fitted an aux. coolant pump on the 2.2.

Most engines will see a little rise in the water temperature after stopping the engine. This is simply residual heat in the block and head still being transferred into the coolant but, since the coolant isn't being recirculated, the small amount of coolant inside the engine gets a little warmer. It starts to circulate very slowly due to the thermosyphon effect and the first thing it hits after leaving the engine is the temperature sensor, hence the gauge increases.

During this process the head is simply cooling down from the temperature it was at when the engine was running. Just because the coolant temperature indication has risen, it doesn't mean the head has been cooked. The cylinder head gets much hotter than the coolant when the engine is running, and it has to get much hotter still before it is in danger of warping.

I think auxiliary pumps as fitted to the V6 are only fitted where there is a danger of "after-boiling", where the engine is large enough to hold sufficient heat to boil the coolant before the heat has dissipated naturally. Even then, it's probably only an issue in the warmer climates where the car is sold.

The V6 aux. pump also only really circulates the coolant around the radiator. I doubt much passes through the engine.

In short, I don't think the lack of such a pump has got anything to do with your warped head.

All seems logical and does make sense, however if my engine has not been allowed to over heat, why would the head warp?  I am aware it is an aluminium head, and these things can happen, so is that it?  It just did?  Okay, but why is it so common on 2.2?

[05omegav6]

Have you changed the waterpump recently? Also would fitting a V6 radiator make a noticable difference 

Could also be a dicky temp sensor...

[Kevin Wood]

All seems logical and does make sense, however if my engine has not been allowed to over heat, why would the head warp?  I am aware it is an aluminium head, and these things can happen, so is that it?  It just did?  Okay, but why is it so common on 2.2?

Is it that common, though?

I know the 4 pots tend to suffer HGF earlier than other engines but the wisdom on here is generally that it's not worth bothering to skim them as they rarely warp, so I actually think your experience is an exception, and therefore unlikely to repeat itself.

Also.. it's not just heat that can warp a head. Uneven clamping forces on the head due to incorrect torquing / removal of head bolts are another example. Can you be sure that your head was not subject to this earlier in its' life?

[philsteward]

Have you changed the waterpump recently? Also would fitting a V6 radiator make a noticable difference 

Could also be a dicky temp sensor...

Water pump was changed 1.5 years and 15k miles ago.
I have just changed the radiator (as the pressurising coolant system made a crack in the plastic at the top) and fitted one which has the connections for the oil cooler on the rad, I assume therefore it is actually a v6 one as well.
Temp sensor - this raises happily, and gives no odd readings, it does however only get to 85 and sit there, not 90 which is half way up the gauge, and I have recently fitted a thermostat so should be reading correctly. If the air con is not on, the temp does rise to 90 on the gauge and the fans kick in then it comes back down to 85 again.

[Kevin Wood]

Temp sensor - this raises happily, and gives no odd readings, it does however only get to 85 and sit there, not 90 which is half way up the gauge, and I have recently fitted a thermostat so should be reading correctly. If the air con is not on, the temp does rise to 90 on the gauge and the fans kick in then it comes back down to 85 again.

Sounds like normal behaviour to me.