Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: DerekT on 10 February 2012, 14:33:34
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Hi Folks,
I have an Omega 2.2 CD that recently broke down on the M6. When the AA came out they read the codes from the engine management computer and it was cylinder 2 and 3 misfire.
When he took the spark plugs out of cylinder 2 and 3 their electrodes had completly gone. No inner or outer. What is wierd is that they both went at the same time. Up until the car broke down I had done 250 miles with no problem.
Anyway he replaced the plugs and away I went but every now and again I still get misfires on cylinders 2 and 3.
I am thinking of changing the coil pack and was wondering if you would agree that this is a good starting point?
Many thanks,
Derek
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What codes are you getting?
Also whats the mileage?
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How long had the plugs been in there?
If they weren't past their sell-by date, I would put destruction of 2 plugs down to detonation or overheating, perhaps due to a lean mixture. Being the centre 2 cylinders, they probably run hottest.
I'd be checking for codes and also watching what the fuel trims are doing with a Tech 2 perhaps?
Depending on what happened to the electrodes (burnt away or dropped off) there might be damage in those 2 cylinders now. A compression test might be in order.
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No idea how long old plugs have been in I'm afraid but they are brand new now and the problem still happens under load at high revs. E.G. accelerating up a hill. Mileage is 95,000
My mate is away with the code read so I can't get the codes just I'm afraid, will get them at the weekend.
I just fitted another coil pack and the symptoms are the same. When fitting a noticed a little oil on the spark plug in cylinder 2, all the others are clean
All the best,
Derek
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Guys,
Just thinking if I have replaced the plugs and the coil pack, can I eliminate these as the cause of the misfires under load? Car also sounds quite rough when idling and there is frequent hesitation, worse when engine is hot.
Could this be blocked or faulty injectors on cylinders 2 and 3? Is it worth trying one of those fuel additives to clean the injectors?
Thansk again,
Derek
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Could well be clogged injectors or something else causing a lean mixture - intake air leak, clogged fuel filter, MAF sensor failure, etc. A dose of injector cleaner wouldn't hurt.
Would need a look at the live data to get further clues, I think.
Might be worth pulling the plugs and comparing each cylinder for colour? Do it after a run without too much idling if possible.
A compression check might be a good idea, just in case the plug debris has scored the bore or damaged a valve.
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The coil packs on the 4 pots do tend to start failing around 100k, I replaced mine at 110k due to a very slight miss-fire under load.
Father T's 2.2 also would get occasional missfire on pot 4, new coil pack (well my old one ::)) fixed it.
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Possibly EGR valve failed open causing excess exhaust gas back into combustion chamber diluting fresh fuel mix.
This would "lean out " the mixture causing rough running ( especially at idle ) , misfire and ultimatly plug failure .
EGR didn't show any fault codes on my 2.0 but gave same symptoms ( minus the plug failure .....)
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Possibly EGR valve failed open causing excess exhaust gas back into combustion chamber diluting fresh fuel mix.
This would "lean out " the mixture causing rough running ( especially at idle ) , misfire and ultimatly plug failure .
EGR didn't show any fault codes on my 2.0 but gave same symptoms ( minus the plug failure .....)
Its a 2.2 petrol, it does not have an EGR ;)
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Possibly EGR valve failed open causing excess exhaust gas back into combustion chamber diluting fresh fuel mix.
This would "lean out " the mixture causing rough running ( especially at idle ) , misfire and ultimatly plug failure .
EGR didn't show any fault codes on my 2.0 but gave same symptoms ( minus the plug failure .....)
Its a 2.2 petrol, it does not have an EGR ;)
What's this for then?
http://www.amazon.co.uk/Vauxhall-Omega-Ecotec-Petrol-FuelParts/dp/B005GZ0DFG
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Possibly EGR valve failed open causing excess exhaust gas back into combustion chamber diluting fresh fuel mix.
This would "lean out " the mixture causing rough running ( especially at idle ) , misfire and ultimatly plug failure .
EGR didn't show any fault codes on my 2.0 but gave same symptoms ( minus the plug failure .....)
Its a 2.2 petrol, it does not have an EGR ;)
Mine does Mark! ???
EGR Valve.........: Part Number 17094107
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Possibly EGR valve failed open causing excess exhaust gas back into combustion chamber diluting fresh fuel mix.
This would "lean out " the mixture causing rough running ( especially at idle ) , misfire and ultimatly plug failure .
EGR didn't show any fault codes on my 2.0 but gave same symptoms ( minus the plug failure .....)
Its a 2.2 petrol, it does not have an EGR ;)
::)
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Hi Guys,
Sorry for the delay on the codes. They are:
P0302 and P0303. I am sure these are generic codes for cylinder 2 and 3 misfire. I had my mechanic look at it yesterday and he advises that the codes are too generic and perhaps I should wait until I get a more specific code.
In the meantime a mate of mine says he has a spare MAF sensor and advises trying that. Do you think it is worth a go?
P.S. Still not sure if my car has an EGR or not :)
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Look at this picture, then at your engine.
(http://i219.photobucket.com/albums/cc138/EZ_Pete/a0c3d752.jpg)
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Here's the one on tunnie's old 2.2, from his camcover how-to thread:
(http://images.omegaowners.com/images/guides/4pot_cam_cover_gasket/DSC08407.jpg)
::)
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Thanks Abiton, I have located it now. A picture speaks a thousand words :)