02 Audi A4 3.0 Quattro

so ive had a misfire that lasts a few seconds every time i cold start the vehicle..

I finally purchased a scanner last week (always wanted one)..

code read 'cylinder 5 Misfire'

the easiest thing that i know that can cause a cold start misfire is a leaky injector. so i ran a bottle of seafoam through a tank of gas and it didn't help. so i removed my fuel rails and primed the pump to look for leaks.. no leaking injector..

so yesterday i swapped cylinder 5's plug, coil, and fuel injector with cylinder 4 HOPING to see cylinder 4 start misfiring..

still misfiring on cylinder 5..

I kinda feel like the next step is the head gasket, but i thought i'd post and see what everyone else thinks first..

here's for hoping i've overlooked something major

 

Have you tried swapping your coils to see if the issue follows it?

 

Do a compression test/leakdown test

 

Also, start the car and remove cylinder 5 spark plug. Do you see spark?

 

Yes, i swapped the plug, coil and fuel injector with cylinder 4 - no change

 

I haven't, but as i swapped everything with cylinder 4 and its still missing on cylinder 5..

but like i said, it only misses from a cold start for about 5-10 seconds.. otherwise it runs without any issues.. my exhaust smells like gas when its missing, but as i've inspected the injector and know its not leaking.. i suspect the gas smell is simply it not firing on that cylinder.

 

I figured you had done this already. You seem to be a pretty smart guy from your other posts, but I know I have a bad habit of forgetting the simple stuff from time to time so I figured I would suggest it.

 

The German guy at import specialists suggested running a oil system cleaner and if that didnt help it could be a cam tensioner..

What do you guys think?

 

I don't know about the cam tensioner. I would think you would get all kinds of weird stuff from that bank of cylinders if that was the case. I'm guessing in theory you can swap them out from one side to the other to see if the problem goes to the other side, but that's a lot of work for a "maybe".

 

hey man i read another post about a guy with the same problem he inspected the cylinder with a high powerd light and saw debreed stuck to the sides so he cleaned it with a shotgun cleaning kit and it solved his problem, just a thought bro.

good luck.