Audi A4 2.8 Quattro Engine Misfire - ChasG
Can anybody help? I have a '98 Audi A4 2.8 Quattro, 78,000 miles. Engine started misfiring on 1 cylinder. Took into garage and they say oil and water is mixing. They took the head off and valves/seals showing some signs of wear but they also think there is a piston problem potentially. Has anybody experienced something similar? It seems to be foxing the garage as to what the problem really is...
Audi A4 2.8 Quattro Engine Misfire - Vagelis
Assuming its a diesel engine (from your "oil and water mixing" phrase), and that oil and water aren't indeed mixing, I would say that it's a compression leakage problem. It'd better be the head gasket, because if it's the piston / piston rings, it's going to be dearer. BTW, are the injectors clean?

Vagelis.
Audi A4 2.8 Quattro Engine Misfire - ChasG
It\'s a petrol engine 2.8, 6 cylinder. Is it still possible it is the injector? I was running quite low on fuel when I first heard the misfire.

charles
Audi A4 2.8 Quattro Engine Misfire - Vagelis
If it's a petrol engine more factors come into play. Electrical.

But since the garage removed the head, I assume that they have already examined spark plugs, coil packs, etc.

It could still be the injector or a cylinder problem (gasket, piston rings, etc.)

But what nags me is that most of misfires on petrol engines are due to electrical or fuel supply problems. And there is the famed problem of VAG coils failing.


Vagelis.
Audi A4 2.8 Quattro Engine Misfire - John F
Chas,

I would be interested to hear what happens - I have one of these engines in a 98 A6, 83,000. Is yours a 30valve? They are relatively rare in this country, mainly in A8s. Do they have a head problem? Do they have the notorious coil packs?

Regards, JohnF
Audi A4 2.8 Quattro Engine Misfire - DL
Was it a permanent misfire or was it intermittant?
Audi A4 2.8 Quattro Engine Misfire - ChasG
permanent!
Audi A4 2.8 Quattro Engine Misfire - Aprilia
There are so many potential possibilities that 'diagnosis at a distance' is impossible. I think you have to put your faith in the garage. Surely they did full electrical tests before taking the engine apart?

You'll need very deep pockets though, the cost of an engine rebuild on one of these must be pretty horrifying.
Best of luck with it.
Audi A4 2.8 Quattro Engine Misfire - DL
I'd really hope (for theirs and your sake!) that they carried out a compression and cylinder leak test. This would have indicated where the compression loss (if any!) was going....

After all, it *could* be an electrical fault.
 

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