Hi guys,

I am looking for some help with a couple of issues I got with my 2002 A4 3.0Q. I would appreciate any input you may have...

1) Every now and then (1-2 times a week) I get misfires in all 6 cyls, according to the code scanner. The car starts to shake, "check engine" light flashes, then after 10-20 seconds this all goes away. "Check engine" light may stay on for another day or so. When it happened the 1st time a few months ago, I freaked out and went to an Audi dealership. Their computer showed a misfire in every cylinder.

They asked me where I filled up; I said I had always used BJ's wholesale club. They told me to quit doing that and start putting in decent gas (Marathon, ExxonMobil, etc). Since then, I have never filled up at BJ's - I now always use Marathon, BP, Shell. But the misfire problem keeps happening (I've done the scans again - it's always multiple misfire codes)! It seems that it is totally not related to where I fill up, how I drive (it usually happens at low speeds), what the temperature is, etc. What in the world could this be?

(also note that I always put in 93 gas, replaced spark plugs (now iridium)/air filter/fuel filter about 20K miles ago.

2) My Xenon lights... when the car is idling, their light is "shaky." Maybe it is all the time, but there is no way for me to see it when I am driving. If these were conventional lights, I would have thought of a poor contact between the bulb and the socket where it fits into... but with these?..

Thank you for your help!

 

Have you tried changing the coilpacks?

 

seems unlikely that all 6 coil packs would go bad at once. to replace all them would be some real pricey troubleshooting. Are you sure that you are getting misfires from each cylinder? Or does the code just say "random/multiple misfire"
If you get a misfire fault code for each specific cylinder then id first replace the plugs and make sure they are gapped right and go from there.

 

pull the codes again and post them all. It makes a difference which ones you are getting.

 

No, I have not tried doing anything with coilpacks - to be honest, I don't even know what they are. As far as codes go, when I had them read the 1st time at an Audi dealership, the computer displayed:
Cylinder 1 misfire
Cylinder 2 misfire
Cylinder 3 misfire
Cylinder 4 misfire
Cylinder 5 misfire
Cylinder 6 misfire

2 more times I had the codes read at Autozone and didn't see what the scanner actually said... but was told "multiple misfires," so I assumed it's the same thing. This happened again yesterday; I will go to Autozone again today to have the codes read. I'll try to get the exact codes this time.

 

How many miles on the car?


Looks like you have done the routine maintenance fairly recently.

I'd run some fuel injector cleaner through the system (eg Techron or redline)

Open the hood and recheck all the vacuum lines and rubber hoses in there, especially the underside for any cracks..

 

change your fuel pressure regulator! that happened to me once. dont waste time and money replacing tha coil packs. misfire on all cylinders usually means it's the fuel pressure regulator. it's either drowning or starving the cylinders. usually coilpacks dont all fail at tha same time.

and i also suggest replacing all spark plugs if you havent done so.

 

and as for your HID's shaking, i have no cluee. lol