Cylinder Misfire Problem

[ivantheterbl]

So since June I have been having repeated problems with the check engine light coming on in my Audi and am wondering if anyone one here might be able to help at all. I will try to post all of the relevant info I can below, any help would be greatly appreciated! --I purchased the car in July of 2010, and when I purchased it the dealer informed me it was fine to put 87 gas in the car. Therefore up until this summer I have been putting 87 gas in --In March the check engine light came on, and the dealer said it was a cylinder misfire. This actually happened right before I was to leave town for three months, so I figured I would deal with the situation once I was back. --The car sat from the middle of March until the middle of the middle of June, never being run --Once I got back I took the car to a certified audi repair shop,and they said the first thing to take care of was replacing all of the spark plugs and to see if that helped. -- The check engine light came on again after about three weeks, and this time the shop went ahead and replaced the ignition coil for cylinder three, which was the cylinder that had misfired --This again worked for a while until the check engine light came back on--It was at this time that I was informed the car needed to use 93 fuel and I was given some fuel injector cleaner which took care of the problem --At this time my engine coolant level dropped low when I was driving somewhere and I had to fill back up the coolant (This is late July) --Everything was working fine with no problems until early September, when again the light came back on and the coolant was low --I figured that the coolant was possibly leaking into the cylinders and took the car to a new dealership, but they informed me that there was nothing wrong with the car and the pressure test they had done indicated there was no leak (the check engine light had been another cylinder misfire) --The car ran fine again for about a month until it recently came back on, and I literally do not know what to do When the cylinder misfires, the car shakes a bit at startup and the exhaust is sometimes a very thick white (which is why I thought it might have a cracked cylinder head but the dealer said they pressure tested for over an hour and everything was fine) I know this is a long post, but ANY help at all would be much appreciated, thanks-- Also, totally forgot to mention but the fuel pump gave out in mid-August, not sure if it is related

[avant_style]

I am having the same problem. I just bought a 98 a4 avant 2.8. it has started idling when started and when when stopped at a stop light. not sure where to start, as this is my first audi ive owned. my plan is to replace spark plugs, clean and set throttle, replace vacuum lines, and then coil packs. did you have any luck?

[jerry-lincoln-ne]

I have an 05 A6 3.2 with 89,000. Same CEL issue. The following projects are now in progress.

1. Timing chains stretched. Replace all timing chains ($7,000).
2. Cracked cylinder head. Replace ($2,500).

[zarati]

I've found the 2.8v6 to be very finicky with plugs.
When I got mine it had "NEW" Plugs. Similary misfire issues.
Checked them and they were not the OEM NGK Plugs. I changed them out and the problem went away. I've found this on more than just my car since then. If the shop used anything other than OEM Plugs, then change them again.