engine sputtering/backfiring no CEL or obvious dianosis - help needed!
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engine sputtering/backfiring no CEL or obvious dianosis - help needed!
Just started today. When idling, the engine sputters a bit and the rpms drop then pick back up again. This isn't consistent - sometimes it idles fine - even tried it in P, D, and N.
When I start from a stopped position, the car sputters and it seems the engine is misfiring a bit. Then beyond 3k rpm it seems to go away. CEL is not coming on, and nothing on the dash is indicating a possible problem.
I do not have a VAG tool to check codes. I am thinking spark plugs need to be replaced? I suspect these have not been replaced in 30k or so. My car just turned over 90k and I just spent a whole lot o' money on 90k service.
Anybody have any suggestions as to what I can do myself before taking it back to my mechanic? While I am no mechanic myself, I could do a plug changeout - any advice?
When I start from a stopped position, the car sputters and it seems the engine is misfiring a bit. Then beyond 3k rpm it seems to go away. CEL is not coming on, and nothing on the dash is indicating a possible problem.
I do not have a VAG tool to check codes. I am thinking spark plugs need to be replaced? I suspect these have not been replaced in 30k or so. My car just turned over 90k and I just spent a whole lot o' money on 90k service.
Anybody have any suggestions as to what I can do myself before taking it back to my mechanic? While I am no mechanic myself, I could do a plug changeout - any advice?
AudiWorld Super User
Joined: Mar 2005
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replace spark plugs first
if you really don't know when the spark plugs have been changed i would start there. You really need to VAG the car. Look at my sig below for links. You could need a new MAF but fault codes and new spark plugs would make it much easier to diag.
AudiWorld Super User
Joined: Oct 2001
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From: SF Bay Area, CA
90K service should include plugs...
Look at your service tag, since plugs are changed at 30K mile intervals for many Audis of this vintage. If not plugs, look for a vacuum leak or maybe the ignition module (I don't know if your car has coils on plugs or the separate coil module like the C4 A6 2.8 I had).
Some codes for these kinds of things take two full cold to hot cycles to throw, so don't be surprised if it takes a few days to see the CEL light up.
Some codes for these kinds of things take two full cold to hot cycles to throw, so don't be surprised if it takes a few days to see the CEL light up.
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Re: 90K service should include plugs...
Yes, good to know. Thank you for the info.
I scheduled a plug changeout tomorrow morning since I didn't have the extension tool needed to reach those suckers.
Hopefully I can replace the wires at a later time after my wallet recovers from the recent timing belt work I had done.
Thanks again!
I scheduled a plug changeout tomorrow morning since I didn't have the extension tool needed to reach those suckers.
Hopefully I can replace the wires at a later time after my wallet recovers from the recent timing belt work I had done.
Thanks again!
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Joined: Sep 2006
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Re: engine sputtering/backfiring no CEL or obvious dianosis - help needed!
I have been having the same problem for about 2 months. i have a 1999 audi a6. I have taken to get check multiple times and they were not able to find the cause. The problem began when i got my water pump replaced at the same time i have my 100k checkup where they replaced the timing belt. When you replaced the spark plugs did that fix the problem? Or is the timebelt linked to the problem? anything thoughts would be appreciated. Thanks
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