Violent shaking...not good

[cujo05]

Leaving my neighborhood today and while accelerating felt a sudden onset of shaking and vibrating through the pedal, wheel, seat...everything. Able to turn it around and make it back to my garage. There remains an aggressive vibration in park. Once it is placed into D or R the vibration turns to a violent shake. The belt tensioner goes ape-shit as well. I've searched several threads on here but am not yet confident as to what is going on. Car is 2005.5 B7, FWD, just over 100k, 2.0t. Wanted to get some more feedback before I start breaking it down. Oh yeah, it also throws the code P0304, #4 misfire. That's using the code ready from Autozone, which I swear is the same code it throws no matter what has been wrong with the car in the past. Needless to say, I'm not convinced that code is relevant.

[Andrew149]

Replace all 4 coils pack and spark plugs.
Jhm has plugs and coil packs for a great price.

[aluthman]

Sounds like a bad coil to me. Swap the coil packs around and see if it throws a code for a different cylinder. If so, replace the bad coil (I recommend replacing all of them).

[cujo05]

Changed coil packs around and still throwing #4 misfire. Swap the spark plugs around?

[aluthman]

Yeah try swapping plugs.

[cujo05]

Swapped coil packs only, misfire #4 remains. Swapped plugs only, misfire #4 remains. Any other thoughts? Thanks so far, by the way.

[Andrew149]

Umm, cut wire in the harness?

[kegobeer]

Check the regional board and find someone local with VCDS, there might be other codes being thrown that you can't see.

[cujo05]

Agree. I swear P0304 gets thrown on the Autozone readers all the time in the past when it's had nothing to do with it.

[aluthman]

Could possibly be a bad injector on cyl. 4. It's a long shot, but possible. If you need a good used stock injector, I have 4 of them.

[cujo05]

Would that cause such a violent change in the amount of shaking/vibration just going from park to drive or reverse...I'm not actually moving, just shifting the selector into gear?

[DannyDeez]

Im not too familiar with this car yet, but my B5 S4 had the same issue one day and it turned out to be the ignition control module (ICM). Its a small part but I couldn't tell you where to find it on this car. I think it was mounted on the air box on my B5. Maybe try to locate it and give that a check?

[cujo05]

I get search hits for ICM on older VW/Audi models, but not on the B7 2.0t. Would this part be called something else by chance? From another thread I think I can trace the wiring from the coil packs back to their origin and locate the "ICM" or whatever its termed. From there I might be able to check things.

[Jovan]

Change the coil Ignition again, i got brand new ones and day after one went out again, My car was shaking horribly on acceleration.

[cujo05]

You misunderstood...I didn't get new ones, just changed around the ones I had. Theory being, if one was bad the code being thrown would come from a different cylinder after I moved it. Despite changing coil packs and spark plugs around I still get #4 misfire. Now, that being said, I reiterate I'm not confident in the code and may change all the coil packs and plugs just for the hell of it to see what happens. I'm not holding my breath...

[DannyDeez]

I get search hits for ICM on older VW/Audi models, but not on the B7 2.0t. Would this part be called something else by chance? From another thread I think I can trace the wiring from the coil packs back to their origin and locate the "ICM" or whatever its termed. From there I might be able to check things.

Yea sorry man I have no idea on this car. What about this: http://www.ecstuning.com/Audi-B7_A4-Quattro-2.0T/ES2779675/
Just from reading their description - "If the engine is revved with a worn sensor, misfires, motor vibrations and backfires can occur. "

Like I said, Im really not familiar with this car yet. Just throwing things out there that might steer you in the right direction.

[groundround]

Carbon build up, it starts misfiring on one cylinder and over time will hit others. Vibration, shity idle etc... Just a guess, also maybe dirty ma for both

[JayDog747]

Is this a CVT?

[cujo05]

Bought brand new coil packs from O'Reilly (yes, I know not from Audi but they were closed and wanted to change them so...), new NGK copper plugs. No codes and runs fine so far! Much thanks to all who replied and hopefully will aid someone else in the future. For the record, a very easy fix and set me back about $120 for all parts. Anyone with even minimal mechanical know-how can do this. Again, mad thanks to the Audizine members and the DIY's.

[DannyDeez]

Glad you got it sorted out [up]