pava12

either me or a6fun have ignition coils ,wich reqiure no special wires , in my case i went and cecked and replaced sparkplugs and coils and not only .the basics are like you say it but the trouble seems to be further down the road .i was out of ideas and still ...am .

pava12

UPDATE, before you go to the mechanic again ceck the battery and see if it's working ,it might start the car but maybe cannot sustain the consummers ,i did go today to the autozone for a free test , mine was bad ,so i went ahead and filled the old battery with water (mine allows that )and to my surprise no more missfire for now .And all the respect for the suggestion that we are looking at the moon ! i'll keep you updated about any changes in behavior .thank you.

A6FUN

Thought I would check in with the latest on my misfire problem.
Last inspection of cam tensioner did not reveal anything.
Left bank misfires only above 3000 rpm.
Car now has 273,000 km. Recently changed spark plugs and ECT sensor (engine coolant temperature). Strange thing happened, misfires still happen above 3000 rpm but now under hard acceleration. Light did not trip as easily. Good for a week or so then battery starting acting up (not holding a charge) and light would trip more often. Replaced battery and again light would not trip as easily.
Car has a definite hesitation/miss and paying closer attention to the tach, the rpms actually seem to stall momentarily at about 3400-3500 rpm when accelerating.
No other codes or side effects from this mysterious problem.

pava12

Hello again , i have no missfire since i added water to the level in my old battery i drove like that for some time then i bought a new battery , no problems again .Mine do not hesitate under load anymore .Visually ceck the voltmeter on the dashboard to see where the needle stays it should stay about 14V without electrical consumers turned on ,with consumers needle will drop a bit .If it does not stay there i suppose you can ceck alternator or alternator wiring .I did ceck mine at autozone for free .please ceck if replacement battery is exact replacement for your car, hope this helps .

A6FUN

Long overdue update (misfires cyl. 4,5,6).
After lots of procrastination and mileage now up to 295,000 km, finally got the car back to my mechanic who dug into the engine further.
First found a "melted" cam sensor. Once replaced, started throwing cam timing error. Looked at cam tensonier and found chain rubbing against cylinder head, replaced cam tensioner.
Also replaced left bank downpipe and catalytic converters due to previously poorly done flex pipe repair (muffler shop).
The good news is no more cylinder 4,5,6 misfires BUT the bad news is now throwing right bank misfires (cyl. 1,2,3) a just above 2000 rpm (2000-2500 range).
Very frustrating.
The mechanic working on the car suspects that this engine might have thrown a timing belt in the past and some slight damaged part might have been missed in the repair.
Now ... what to do next ......?

A6FUN

One last update to close this thread.
Mechanic looked into the right bank misfires and found that the chain for the cam tensioner was off by a link. I hope I have this right based on the mechanic's description.
Anyways, engine misfires finally gone. Drove car up to 340,000 km, sold the car and bought a 2004 A6 with the 4.2.
No check engine light on this one ....... so far.