Misfire in cylinder 7 part 2 (need some help figuring this out)...

[...Mark...]

Heres the time line... BTW its an 04 S4.

Monday night - Started the car up to leave work and the car was running rough. Stopped by autozone and the code was for a misfire in #7. Picked up some plugs while there, went home and swapped out the right bank because thats were cylinder 7 was. I only did the right side because i wanted to grab an air filter the next day seeing that you have to pull the airbox to get to all of the plugs on the left side anyway.

Tuesday morning - Cars running fine, so on my way to work i stop to get an emmisions test done because i need it. Car fails because codes hadn't cleared.

Wednesday morning - Go back to the emissions place and have it retested and everything is OK and it passes. I then grabbed an air filter from the dealer and head to work. Cars still running fine.

Wednesday night - Swap out the plugs in the left bank and drop in the new filter. Take the car for a ride real quick after everything is done, and the car is running fine.

Thursday morning - Start it up, and its idleing rought again. Go back to Autozone and once again the code is for a misfire in #7..


What does this all mean? I'm thinking its the coilpack thats cutting in and out because its on its way out. Then again i am concerned that may not be the case because it drove fine for 2 days after the plug was changed. What are your thoughts.

TIA.

[40valve]

It could be coilpack. When 2 of mine failed I got a CEL and car was fine for few minutes then it started to idle really rough. I drove to the dealer which was about 30 miles, through stop and go city traffic and it ran just fine. As soon as I pulled in the dealership it started to run rough again.

[...Mark...]

I'm thinking of swapping two of the coilpacks to see if the misfire changes from one cylinder to the other.. If it does, then i'm thinking i will definatley know thats my problem.

BTW thanks for the write up on the filter.. I had that thing in and out in 20 minutes..

[...Mark...]

Also who has reasonable pricing on the coil packs. I'm thinking i am going to change the one today regardless in the hopes that it is the issue, but i definatley want to do the other 7 asap so that i don't have the same issue pop up down the line..

[joeycuccaro]

Sounds like a coilpack to me

[40valve]

I can't remember if your car is CPO or not but if it is then the dealer should cover it.
Mine replaced all 8 at the same time. I was shocked. Buddy of mine was working there at the time so that might've had something to do with it hehe

[Jdubya]

I got the new style red tops from ECS tuning for $30 a pop.

Swapped all mine out.

[3 bar]

My #7 and # 8 went out at the same time. It seems like the rears go out 1st maybe due to excess heat.

[...Mark...]

I got the new style red tops from ECS tuning for $30 a pop.

Good to know.. I changed it this evening and it running strong again.. I hoping this was the problem.. We'll see.

[Swanky]

I got the new style red tops from ECS tuning for $30 a pop.

Swapped all mine out.

can you show me a picture of the "original coil pack" and then the "updated coil pack"? I am curious... I think this is the "updated coil pack" pictured below with the grey top

[Jdubya]

That's the new Q version. Those are the ones I bought.

[...Mark...]

I think this is the "updated coil pack" pictured below with the grey top

Thats what the dealer gave me. The old ones were black, the new i believe are gray.

[Swanky]

k thanks

[nssaudi]

Anybody know what are the design differences between the new and old coilpack?