Need Advice - Crazy Vibration with throttle applied - CVT
 

Hi guys

At this point I really need as much help as I can get.
Here is the issue.
Audi 2002 A6 3.0 CVT

Crazy vibration even at low speeds (30 mph and up to 80+mph) when throttle is applied.
It seems like coming from he right side of the front wheel.

Even though the cult-print of the phenomenon doesn't seem to suggest that the wheels have a balance issue, I had a shop lifting the car checking the wheels.

background information
1) The car just had alignment - I though that they forgot to tight the alignment bolts or something like that but when I took it back to the shop they said that aliment can't do that and that it's probably the transmission (?)

2) I have the CVT transmission - I tried switching from auto to manual and to different gears - the vibration intensity is the same regardless.

3) The car is FWD and I had a blown tire so I was using a different size tire in the front right wheel. One of these days it was raining and I experienced torque steer while accelerating in straight line. I kind of kept my foot in throttle instead of backing off so now I'm wondering if I damaged the engine mounts.

Just to clarify I now have the vibration with same size wheels at the front (I put the rear wheels at the front and the front to the rear until I get my new tire).

Is broken engine mounts something common in A6s? How can I test for that? I know in manual cars you put the car in first gear and you release the clutch while applying the brakes - I can do the same on my CVT but I just want to check the common knowledge here since I know that these transmissions are a bit sensitive.

What else do you think it can be?
Do you have to suggest anything else to test?
I love my car but a new CVT tranny is like $9K so I need to figure out whats going on and if I need to get rid of my baby :-( .

Thanks,
Chris

could be bad driveshaft, if the shaft boots are intact, possibly internal shaft join is bad or piece that dislodged inside , that could cause bad vibration,

ibration could still be the wrong sized tire..... get a new one, i mean come on even used tires are like 30 bucks ya cheap skate

->2.7L turbo: I got a used tire and had a sidewall damage (bubble) so I remove them and I asked for my money back.
Got my money back got a second used tire which again had a bubble!
Asked for my money back and got my money back for second time (btw different sellers).
Now I got a third used tire and I'm waiting for it...

I'm not cheap but I wouldn't like to have a new tire at one end and 3 60% worn tires everywhere else. Also I'm not crazy about these tires (Pirelli P6) so I don't want to spend $400 to get two new ones. If I had to change them I would prefer to spend $500-600 and get fresh stickier tires all around. So at this point - and since this is not a race car I'm trying to get a used tire in similar size and condition. If I'm unlucky for third time I'm not sure what I will do...

What I can do to test your theory is to put the right size wheel (with the bubble) and see if the vibration continues.

I was wondering if the motor mounts can introduced this kind of vibration.
Here is a video I took with my left foot on the brake and the right foot applying the throttle. This isn't a racecar but a smooth cruiser so I would expect some movement from the engine but I'm not sure if this much movement is allowed... maybe someone with more experience can advice....
here is the link (I hope it works):
http://www.facebook.com/video/video....omments&ref=nf

unfortunately there are ALOT of potential points to induce vibration to the car, without sitting in the car first hand, its tough to say. i would eliminate tire size and wheel balance as the issues, then start looking at TREs, control arms, and motor mounts next

If you don't get the vibration in neutral but only with throttle applied chances are the output cups or spider that gozinta the cups on the output drive flange on the transmission are worn.

One thing you could do is put the front of the car up on jack stands (under the bj, support the lower control arm at the spindle) and run the wheels in gear with the engine. Observe/listen.

If the wheel bounces around like crazy it's out of balance or a bent wheel. Also check tire for out of round.

Lastly, with engine off, try rotating the wheel back and forth and see how much play is in the drive shaft...there should be essentially none.

Maybe you have loose lug bolts but since you've done multiple tires...probably not.

I'll check these tonight John.

By the way it all started after I gave the car for alignment and I kind of feel that maybe something happened there. There was a clanking noise coming from the steering while turning (after the alignment was done). That makes me think that I might also need to adjust the steering rack preload – moments like these I think that having the car serviced at the dealership is not a bad idea…

I also noticed that the vibration goes away if the wheels are slightly turned not sure from what direction – I need to confirm that.

suspension or driveshafts then

Hey Max

Unfortunately that would not even guarantee a proper fix, trust me...

I had a similar issue and it turned out that one of the tires were mounted the wrong way on the rim (directional thread). Not sure if this could be it as yours started so sudden. Also, try to swap the rear wheels to the front to see if it could be a bad wheel. Mine is quattro and I had to get the tires balanced 3 times, the one time, to get rid of a vibration.

Hope that helps

Cheers
Massboykie

I get a vibration around 2k to 3k rpm. My motor mounts are shot. It all came about after changing all my control arms. Parts are cheap, labor is what's holding me back. Getting Apr mounts. Also changing snub mount while I'm there.