View Full Version : 2004 A4 1.8T Idling Rough

08-10-2010, 08:00 AM
My car has been idling rough for a while now but runs perfect when driving the car and when the air conditioner is running really odd and the chek engine light is on but not flashing and i have hooked it up to VAG Com and its says cylinders 3 and 4 are missing and that it is running lean. I have Taken the throttle body off and cleaned it completely, replaced all coil packs, changed spark plugs, and pulled the MAF and cleaned it also. I have checked all the VAC lines that i can see and they all look really good. I also ran sea-foam through the intake it and put it in the tank when i filled up last. nothing seems to help at all i have read other post and have checked everything i can think of and what other people have said and was wondering if anybody has any other suggestions for me to try? I am pretty mechanically inclined and don't want to spend the money at the dealer if i can do it myself.

08-10-2010, 08:13 AM
Well one thing you should be aware of is that this is the B5 section and you own a B6 which means you will get better results from your queries there. Admittedly they are extremely similar in almost every way except for mainly the body but still, there are some small differences which makes posting there the better idea. B6 Section (http://www.audizine.com/forum/forumdisplay.php/4-B6-A4)

It's also a good idea to become better acquainted with the people there as it's a pretty happenin' part of the forum right now (and will continue to be) and some of the best people on the planet are among their posters. I'm sorry if you were a lurker before and already know all of this but bases gotta get covered.

Unfortunately after posting all of that I need to inform you that I have absolutely no idea what's wrong with your car. Good luck with your problem and welcome to the 'Zine.

08-10-2010, 08:32 AM
replace your coils on cylinder 3 and 4.

08-10-2010, 08:36 AM
THank you very much

08-10-2010, 08:40 AM
I would check gaps on plugs, swap the 1-2 coil for the 3-4 coil and see if it also swaps misfire code. Also try tb adaption. Also how does air filter look?