I'm working on a 2000 A6 with the turbo V6. The driver side is misfiring on 3 cylinders.
Codes..
16684 Random misfire detected
16688 Cylinder 4 misfire detected
16689 Cylinder 5 misfire detected
16690 Cylinder 6 misfire detected
18010 Voltage supply terminal 30 voltage too low.
Last code is from dead battery. Alternator works fine..
Both the modules on the air box are brand new from the dealer. I replaced them because one went bad and the car ran good for a few months after.
I've swapped the plugs around on the modules to make sure the problem did not move over to the first bank. Nothing changed.
I've done a compression test with positive results, I checked the cams for proper alignment with a special cam tool for that engine and it checked good.
I confirmed all 6 coils are good. I've wiggled the wiring harness to see if anything changes while running and nothing.
I posted this on Audi Forum on Friday and nobody's responding.. So I'll see what happens here lol
I'm at my wits end with this, but convinced its a electrical issue.

 

I grew up with a certain mechanic that runs his own volks/audi/porsche shop. i used to hang out there a lot. hes got a 400hp TT. anywho, i know this for sure...he was ALWAYS putting in new coils or soldering new peices into the harness on some car or another. but, he also had/has the latest software/scanners for dignosing. and if hes not doing that, hes replacing the lifter pucks in the tdi's.

sorry i can't help dude, good luck.

 

Tell me about it.. These cars just can't seem to stay outta the shop, very problematic.
This car was at the dealer and they could not pin point the issue.
I spent a long time searching on this and came up with nothing.

 

I had a similar problem. Was the vacuum system. 600 dollars later and it was fixed. Sold it a week later. Thank goodness!!!

 

just posting links so I can go through them later.

http://www.audi-forums.com/archive

http://www.justanswer.com/car/expert...questions.html

 

This forum is no help at all lol

http://www.audiforums.com/forum/audi...1/#post1426672

I'm jDan

 

just as a test, when youre over in the audi forums post up a question about jeeps see what happens. LOL

 

Lol I should do that and see what happens.

 

Well.. I'm gonna pull the cat off that's at the turbo to see if its clogged.
I just remembered this car had cat issues that were never fixed.

 

I pulled the O2 out of the bank 2 cat and cleared the codes and ran it. Same codes came right back with a flashing engine light "means misfire"..

Really not liking this car... I'm definitely missing something.

 

can you put noid lights on the injectors?....or even swap them side to side?
how did you confirm the coils were good?
did you pull them out one at a time leaving the plug in and crank it making sure it was grounded?
i've read about bad pvc's causing a lot of oil in the cylinders...
have you compared sparkplugs from bank to bank?

 

I swapped the coils to the other side and got same results. The plugs look healthy.. I did put manufacture specific plugs in and properly gapped with no changes.

I have not tested the injector signal yet though.. But I could smell the unburned fuel over working the cats so I figured they are working fine.
I'll check that tomorrow.
I'm not in a rush to fix this btw.. I prolly spend a couple hours on it a week.

 

Injectors are working. I put a stethoscope to all 6 and they all sound the same.

Tick tick tick tick tick.... Lol

 

Just checked this... NOTHING. I'm starting think these guys just bring their **** to a mechanic lol

 

does it misfire at idle only or all the way through the rpm range, judging by the codes you posted you have vagcom yes?