Hi guys.
I have a little information to shed on the situation.
I have a 2005.5 A4 2.0T Avant (B7). Battled with the dealer on several occasions regarding the engine vibration at idle. Motor mounts replaced.
They drove another model on lot and considered it 'acceptable' and 'comparable'. Load of BS to me.

Regardless, took the car to my buddy who specializes in Audi/BMW.
Snub looked fine. Loosened all mounts after jacket. Lowered the car and drove in the garage to let the car settle. Miraculously, VIBRATION WAS GONE! We tightened things back up and alas, the vibration had returned.

Our thoughts: MOUNTING ISSUE. We've pondered the subframe mounts or the bushings. ? I wonder if any luck with Audi CPO warrantee I'm working with right now.

I know this thread is getting a little long, but does anyone have any thoughts? It appears as though Audi recognized an issue with the vibration. This model year had a mod to the engine with some type of vibration dampening component to the engine. Don't know much about it but it is in the mechanic guide for updates for that model year.

Thanks for your help.

 

MiguelG,

Thanks for the info. This "subframe mount" theory sounds interesting... Anyway, this is maybe the only thing I haven't tried so far.

So, please, keep us posted.

 

I was at the gas station filling it up with PREMIUM and looked over and saw a container of Octaine Boost. So for $4.00 bucks I thought it won't hurt....
Much to my surprise ....it actually calmed the vibration!!! Not totally but its bearable now! Might cost a bit but for $4.00 a fill I have my sanity back.

Performance is better also.... My next question: If I use the boost each tank fill will it harm the engine in the long run?

 

Any updates? Anyone?

 

I had what sounds kind of similar to this, happen to my 3.0. I could unplug the MAF sensor and the car would run better and throw the code P0171 if I remember right. I plug it back in and the code goes away, but would idle even worse. According to my work order from Audi, I had two of the small vacum lines at the back of the engine that needed repaired and a bad crankcase breather. They replaced vacum lines and the breather. They also said the needed to clean the injection system and replace plugs due to running lean for so long. I did live with it for months, but replaced the plugs the weekend before, so they checked them and they were fine. When I got the car back, the thing ran so much better, I was able to hear the bad wheelbearing. Things have been good since.
I hope this helps someone.