So I replaced the inline check valve that was all crusty and cracking hoping that it would solve my idling vibration problem ... it didn't. [:@]

I hada lot of vibration when driving and at idle ... replaced the busted CV shaft, switching out the motor mounts with 034 street density mounts and an APR snub mount ...the vibration when driving all but went away, but the vibration when idling is still there (even with replacing the busted inline check valve). The vibration does seem to minimize if I put the car in Neutral from Drive.

Anybody got any suggestions on what I should check now ... it sucks to drive an Audi and have a vibration while sitting at a traffic light ... I'd expect it from a Ford or Chevy, but not an Audi.

 

bump

 

I used to have the same problem on my benz C280. The car would vibrate like crazywhen idling at a light. It turned out it was mainly caused by using low grade fuel and 1 coil goingbad.
Is your CEL on? Ifso were u able to pull the codes?
Have you noticed any unusual noises from the engine compartment when accelerating?
On my audi 3.0 everytime I would accelerate I would hear air being sucked in the engine which led me to find the cracked air hose I was talking about in my thread.
Keep in mind that when you have a cracked hose or vacuum leak, your CEL won't turn on.

 

I use high grade fuel ... the CEL isn't on ... it looks like I'm gonna have to check all the hoses. Thanks bro for the info.

 

I had a vaccum leak and my CEL did turn on. It was a busted hose causing the leak.

 

What are you talking about? That your engine runs rough and shaking the car? Or it feels like the motor mounts busted and vibrating in your engine bay?
Just because the check engine light isn't on doesn't mean there aren't any fault codes.

 

With my car, ifI have had some sort of fault codes (mis-fires, etc) the car won't come back to a normal idle (won' stay at a certain idle, rpm not constant, vibrates)until theyhave been cleared... Not sure if that will help, but try getting any codes read and cleared even if you don't have a CEL

 

I have 03 1.8T and I do feel vibrations. Today I tried 94 Octane instead of 91, the vibrations are much better. However, I still feel the engine should vibrate less.

Somebody mentioned that the Coil might be the cause (i do hear some Ticking noises in the engine every 5 or 8 seconds, are these symptomes of coil failure?)

No CEL, VAG-COM scan show engine faults free, no miss-fire.

How do you guys suggest to test if I have a poor Coil? Vacum Leaking (are all the vacum piping on the right side of the engine or distributed on both sides?)

 

Ticking noises are more likely fuel injectors than coil packs.

 

If its the Fuel Injectors, wouldn't the cylinder miss-fire and thus a CEL comes on ?