[V6-12v] Rough Running Engine

Mike Veglia msvphoto at pacbell.net
Tue Nov 3 08:38:00 PST 2009

In a message dated Tue, 3 Nov 2009 David Torrey writes:

<< Are
there any 12 valve V-6 owners left??? I have a rough running engine,
not a dead skip.? I can't fiind any faulty hoses? but it seems to me
that it could be an air leak.? Anyone have any suggestions? >>

We had a hard miss on our 1995 A6q around 6 years (and at least 70k miles) ago now. No codes. I determined the cause was fuel by removing the electrical connectors for each fuel injector one at a time while the engine was running and 5 of the six resulted in a worse idle, one was no change. I ran an extra strong dose of injector cleaner (probably Techron, but a whole bottle added to less than half a tank of fuel). 150, or so, miles later smooth as ever. You might try this even if it is not a solid miss.

More recently EGR malfunctions have caused rough idle (not a solid miss though) but that will throw a code and turn on the CEL. Any codes stored?

HTH and good luck.

Mike Veglia

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