Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: tunnie on 10 March 2016, 22:54:21

Title: Compression Testing
Post by: tunnie on 10 March 2016, 22:54:21
So I've compression tested my trusty steed, have to say there is something about working at night with head lamps  ;D

Now instructions said do it with warm engine, I did it while cold. Any impact?

Results:

Pot 1 = 15.5 Bar
Pot 2 = 15.3 Bar
Pot 3 = 15.8 Bar
Pot 4 = 16.0 Bar

So all consistent and about the same, so it looks like HG has survived?
Title: Re: Compression Testing
Post by: serek on 10 March 2016, 22:59:49
those values looks good :y lucky you  :)
Title: Re: Compression Testing
Post by: tunnie on 10 March 2016, 23:10:16
Next stop, water pump  :)
Title: Re: Compression Testing
Post by: 05omegav6 on 10 March 2016, 23:14:18
Next stop, water pump and cambelt  :)
Just to be sure ;)
Title: Re: Compression Testing
Post by: tunnie on 10 March 2016, 23:24:49
It starts and revs ok so if Cambelt was feked, don't think I would have made it home?
Title: Re: Compression Testing
Post by: Kevin Wood on 10 March 2016, 23:58:41
Water pump wouldn't bother the cam belt if it had just lost its' impeller. Either thst or the thermostat has failed. Was the heater blowing hot after it failed? Was it happy running on lpg?

If yes to both, i'd say the thermostat is favourite.
Title: Re: Compression Testing
Post by: 05omegav6 on 11 March 2016, 00:51:29
Only suggested cambelt as you need to remove it to swap the pump out and if the pump has wept as a side effect then it won't have done the belt any favours...

Thermostat only just been done, no? :-\
Title: Re: Compression Testing
Post by: tunnie on 11 March 2016, 08:38:18
So the stat.... I fitted a genuine GM one bought from a dealer. When purchasing I gave the part number supplied here, parts bloke said it was super seeded with xyz part number. I fitted the stat but it would never go above 75c, in the morning it would get to 75 and stat would open, temp dropped almost to end stop!

So I fitted one from ECP as a test, it's been fine since. (Around 6 weeks ago) Running bang on 85c as it should do, all of the time.

What's best way to test stat? Will it be visually obvious it's failed/stuck?
Title: Re: Compression Testing
Post by: tunnie on 11 March 2016, 08:39:14
Heat was good and it's been fine on LPG  :y
Title: Re: Compression Testing
Post by: tunnie on 11 March 2016, 08:41:15
Also AA bod put a pressure gauge on coolant bottle, there was no change in pressure when the engine was revved?
Title: Re: Compression Testing
Post by: Kevin Wood on 11 March 2016, 09:36:58
Also AA bod put a pressure gauge on coolant bottle, there was no change in pressure when the engine was revved?

Just suggests it's not a catastrophic head gasket failure.

You can test the thermostat by putting it in a pan of boiling water and checking that it starts to open.
Title: Re: Compression Testing
Post by: tunnie on 11 March 2016, 10:48:01
So just for my understanding, with engine at normal temp and everything as it should be. You would not expect to see pressure changes in coolant system under RPM changes?

I'll pop the stat off at the weekend, pop it in some boiling water. I take it I will see the coiled part retract slightly? If nothing then it's stuck shut?

I guess that would give the same symptoms? - Coolant in the engine block gets too hot, the stat refuses to open, thus not allowing colder coolant in from the rad into the block?

Title: Re: Compression Testing
Post by: zirk on 11 March 2016, 11:02:28
Take it LPG's been plumbed in correctly, as you say check Stat first then Pump, but I had a 2.0 LPG from a Member here about 5 yrs back (diagnosed as HG Failure by his Garage, which it wasn't), the thing was all over the place on temperature, especially in cold weather like were having now, changed stat, convinced that was the problem, but latter found out the LPG Vap was furbed and effecting temp.  :-\
Title: Re: Compression Testing
Post by: tunnie on 11 March 2016, 11:04:53
Take it LPG's been plumbed in correctly, as you say check Stat first then Pump, but I had a 2.0 LPG from a Member here about 5 yrs back, the thing was all over the place on temperature, especially in cold weather like were having now, changed stat, convinced that was the problem, but latter found out the LPG Vap was furbed and effecting temp.  :-\


Hummm interesting, not considered that. LPG installed by Lazydocker, so it's about as right as something can get! Never missed a beat since 135k install.

Did he have issues running on LPG with temp over the place? It's running fine on gas or petrol, but having temp issues as described above.
Title: Re: Compression Testing
Post by: zirk on 11 March 2016, 11:13:50
I took it on as possible cheap repairer, (Craig from Watford from memeroy), His Garage had diagnosed as HG fail, sniff test, as temperature would run hot, cold, etc). I wasn't convinced it was HG.

Car would run fine, on Petrol and LPG, would take ages to get warm then overheat, go cold etc, very occasionally, if you took it on a long run (cold weather) LPG would start be hesitant, then switch off, car would get hot again, stop car, wait 5 mins off you go again for any to 10 to 100 miles.?

As said I was convinced it was an iffy stat, and, or, needed a good flush, but as said turned out to be the Vap in the end. 
Title: Re: Compression Testing
Post by: Nick W on 11 March 2016, 11:28:34
So just for my understanding, with engine at normal temp and everything as it should be. You would not expect to see pressure changes in coolant system under RPM changes?

I'll pop the stat off at the weekend, pop it in some boiling water. I take it I will see the coiled part retract slightly? If nothing then it's stuck shut?

I guess that would give the same symptoms? - Coolant in the engine block gets too hot, the stat refuses to open, thus not allowing colder coolant in from the rad into the block?


The pump is for coolant flow. Pressure comes from the coolant heating up in a sealed system.


Your symptoms are a flow issue. Whether that is caused by a blockage(and a faulty thermostat is  the usual cause) or a defective waterpump can only be confirmed by actually checking the car. One of these  http://www.ebay.co.uk/itm/Handheld-Digital-LCD-Temperature-Thermometer-Laser-Non-Contact-IR-Infrared-Gun-/361435030500? hash=item542734e3e4:g:A4YAAOSwosFUXKVK (http://www.ebay.co.uk/itm/Handheld-Digital-LCD-Temperature-Thermometer-Laser-Non-Contact-IR-Infrared-Gun-/361435030500?hash=item542734e3e4:g:A4YAAOSwosFUXKVK) is an efficient way of checking the flow, as you can easily track the temperature of various parts of the cooling system. £11 is dirt cheap for a tool you'll find allsorts of uses for; blocked exhausts, bad wheelbearings, seized brakes, central heating faults are all easily diagnosed and the laser makes a good cat toy.
I think you have a loose impeller on the waterpump, a fault that is becoming increasingly common.
Title: Re: Compression Testing
Post by: Andy H on 11 March 2016, 11:33:48
So just for my understanding, with engine at normal temp and everything as it should be. You would not expect to see pressure changes in coolant system under RPM changes?

I'll pop the stat off at the weekend, pop it in some boiling water. I take it I will see the coiled part retract slightly? If nothing then it's stuck shut?

I guess that would give the same symptoms? - Coolant in the engine block gets too hot, the stat refuses to open, thus not allowing colder coolant in from the rad into the block?
If a thermostat is going to stick shut then it will normally do it from cold.

Have you inspected the pump yet?
Title: Re: Compression Testing
Post by: Sir Tigger KC on 11 March 2016, 12:05:19
I'd flush the rad before dismantling stuff, especially as you need to disturb the cam belt.  ;)
Title: Re: Compression Testing
Post by: zirk on 11 March 2016, 12:23:25
One of these

http://www.ebay.co.uk/itm/Handheld-Digital-LCD-Temperature-Thermometer-Laser-Non-Contact-IR-Infrared-Gun-/361435030500?hash=item542734e3e4:g:A4YAAOSwosFUXKVK
 
Dont tell Him to buy one of them, for Gods sake, He be playing with for weeks, He be posting up all sorts of issues, heated seat temp, wing mirror temp, inner ear temp, LPG tank temp, the list will be endless.  ::)  ;D
Title: Re: Compression Testing
Post by: Nick W on 11 March 2016, 12:28:32
One of these

http://www.ebay.co.uk/itm/Handheld-Digital-LCD-Temperature-Thermometer-Laser-Non-Contact-IR-Infrared-Gun-/361435030500?hash=item542734e3e4:g:A4YAAOSwosFUXKVK (http://www.ebay.co.uk/itm/Handheld-Digital-LCD-Temperature-Thermometer-Laser-Non-Contact-IR-Infrared-Gun-/361435030500?hash=item542734e3e4:g:A4YAAOSwosFUXKVK)
 
Dont tell Him to buy one of them, for Gods sake, He be playing with for weeks, He be posting up all sorts of issues, heated seat temp, wing mirror temp, inner ear temp, LPG tank temp, the list will be endless.  ::) ;D




You've got one too ;D ;D
Title: Re: Compression Testing
Post by: zirk on 11 March 2016, 12:42:42
One of these

http://www.ebay.co.uk/itm/Handheld-Digital-LCD-Temperature-Thermometer-Laser-Non-Contact-IR-Infrared-Gun-/361435030500?hash=item542734e3e4:g:A4YAAOSwosFUXKVK (http://www.ebay.co.uk/itm/Handheld-Digital-LCD-Temperature-Thermometer-Laser-Non-Contact-IR-Infrared-Gun-/361435030500?hash=item542734e3e4:g:A4YAAOSwosFUXKVK)
 
Dont tell Him to buy one of them, for Gods sake, He be playing with for weeks, He be posting up all sorts of issues, heated seat temp, wing mirror temp, inner ear temp, LPG tank temp, the list will be endless.  ::) ;D

You've got one too ;D ;D
No, but as Trigger say's on 'Only Fools and Horses' "Im thinking of getting one though"  ;D

So, why that one Nick, and not one of the cheaper 5/6 quid ones?, or was that an example on ebay.
Title: Re: Compression Testing
Post by: tunnie on 11 March 2016, 12:59:57
Firstly, thanks for everyone's comments OOF at its best  :y

Cheaper one here:http://m.ebay.co.uk/itm/Handheld-Digital-LCD-Temperature-Thermometer-Laser-Non-Contact-IR-Infrared-BIT-/121858599675?nav=SEARCH (http://m.ebay.co.uk/itm/Handheld-Digital-LCD-Temperature-Thermometer-Laser-Non-Contact-IR-Infrared-BIT-/121858599675?nav=SEARCH)

Is Nicks one better quality? Also thanks for suggesting. Looks very useful, will get one of these  :y
Title: Re: Compression Testing
Post by: zirk on 11 March 2016, 13:04:59
Firstly, thanks for everyone's comments OOF at its best  :y

Cheaper one here:http://m.ebay.co.uk/itm/Handheld-Digital-LCD-Temperature-Thermometer-Laser-Non-Contact-IR-Infrared-BIT-/121858599675?nav=SEARCH (http://m.ebay.co.uk/itm/Handheld-Digital-LCD-Temperature-Thermometer-Laser-Non-Contact-IR-Infrared-BIT-/121858599675?nav=SEARCH)

Is Nicks one better quality? Also thanks for suggesting. Looks very useful, will get one of these  :y
See, I toid ya, we'll never going to hear the end of it now.  ::)  ;D
Title: Re: Compression Testing
Post by: Nick W on 11 March 2016, 13:15:10
One of these

http://www.ebay.co.uk/itm/Handheld-Digital-LCD-Temperature-Thermometer-Laser-Non-Contact-IR-Infrared-Gun-/361435030500?hash=item542734e3e4:g:A4YAAOSwosFUXKVK (http://www.ebay.co.uk/itm/Handheld-Digital-LCD-Temperature-Thermometer-Laser-Non-Contact-IR-Infrared-Gun-/361435030500?hash=item542734e3e4:g:A4YAAOSwosFUXKVK)
 
Dont tell Him to buy one of them, for Gods sake, He be playing with for weeks, He be posting up all sorts of issues, heated seat temp, wing mirror temp, inner ear temp, LPG tank temp, the list will be endless.  ::) ;D

You've got one too ;D ;D
No, but as Trigger says on 'Only Fools and Horses' "I'm thinking of getting one though"  ;D

So, why that one Nick, and not one of the cheaper 5/6 quid ones?, or was that an example on ebay.


Delivery times, it's in the UK, the cheaper ones are sent from China.


Mine's Bluepoint, bought off the Snap-On van at least 13 years ago for £30. Which was half the price of the next cheapest I'd seen  at the time. Now, I'd buy a cheap one, as I only use it for diagnostics and that's comparative rather than accurate.
Title: Re: Compression Testing
Post by: tunnie on 11 March 2016, 13:21:12
Ah yes. Point taken, much quicker delivery.  :)
Title: Re: Compression Testing
Post by: tunnie on 11 March 2016, 14:14:30
Much to Zirk's disappointment, I've just ordered one Nick linked to  ::)

Thoughts and actions so far:

 - Sub 25mph, with low RPM, temp stays stable. Higher speed = higher temps, also low speed but under load (ie climbing a hill) also increases temp.
 - Cooling fan even at 95c is not coming on. However it's been shorted out as a test, it spins up fine. 
 - Engine starts and runs well, no miss-fires, it also runs fine on either LPG or Petrol.
 - Cabin Heat is good.

1) Next test I will get to do is putting the stat in boiling water, see if it opens.

2) One test would be to use new thermometer to see how hot rad is when fully warmed up, is it failing to trigger fan?  :-\ That said higher speeds would keep temp down I would have thought, which is not the case.

3) Take cam cover off, so that the new thermometer could get a reading off the water pump.

4) Get a temp reading on the LPG vap.

Any other thoughts?
Title: Re: Compression Testing
Post by: Nick W on 11 March 2016, 14:28:23
Much to Zirk's disappointment, I've just ordered one Nick linked to  ::)

Thoughts and actions so far:

 - Sub 25mph, with low RPM, temp stays stable. Higher speed = higher temps, also low speed but under load (ie climbing a hill) also increases temp.
 - Cooling fan even at 95c is not coming on. However it's been shorted out as a test, it spins up fine. 
 - Engine starts and runs well, no miss-fires, it also runs fine on either LPG or Petrol.
 - Cabin Heat is good.

1) Next test I will get to do is putting the stat in boiling water, see if it opens.

2) One test would be to use new thermometer to see how hot rad is when fully warmed up, is it failing to trigger fan?  :-\ That said higher speeds would keep temp down I would have thought, which is not the case.

3) Take cam cover off, so that the new thermometer could get a reading off the water pump.

4) Get a temp reading on the LPG vap.

Any other thoughts?


Low speed/low RPM doesn't put much heat into the system; just look at how long it takes to open the thermostat when idling.


Cooling fan not coming on at indicated 95* suggests that the sensors are seeing different temps, and they are as far apart as they can be. Likely cause: poor coolant flow


Starts and runs well means it's unlikely to be a serious mechanical fault(head gasket, cracked head etc). You would have mentioned water loss, which is either a visible leak or going out the exhaust/into the oil.


I would normally just replace a thermostat due to its low cost but you've already done so a that, so simple testing is justified.


Use the thermometer to check all accessible parts of the cooling system; hoses, water pump, housings, heater hoses, outlets, various points across the radiator(you might be surprised how a healthy one will measure). This is just a more sophisticated way of feeling the radiator hose for the 'stat to open.


I still think you've got a defective waterpump
Title: Re: Compression Testing
Post by: tunnie on 11 March 2016, 14:32:15
Thanks  :y :y :y

Stat is very new, but just an ECP one, so who knows how well these last. But I would have thought better than weeks!

Still, testing the stat is dead easy and easily accessible on the 2.2. So a nice quick test before disturbing the cambelt.
Title: Re: Compression Testing
Post by: TheBoy on 12 March 2016, 10:45:35
I'd check pump at same time. Quick and easy on 2.2.

You could have both checked in under an hour (double if nursing a Friday night indulgance)