2006 audi a6 multitronic 7 speed vibration

[Matt stone]

Hi guys... I've a 2006 a6 c6 2.0tdi which has a vibration through the car but only under load. It has the 7 speed multitronic gearbox.As soon as you release the accelerator pedal the vibration goes immediately but comes back straight away when you go to accelerate.

You can feel the vibration really bad at 60mph+.it also vibrates when stationary in P R D. Seem to be ok when in neutral.

I did a gearbox oil change with the recommended cvt oil last weekend which made no difference

Any advice would be much appreciated

 

[Sommerfeldt]

Hello!

So, owning a Volvo 850 T5 taught me that throwing parts (and oil) at things without exhaustive troubleshooting first is apt to get expensive really quick.
If you have VCDS, start by seeing if you've got any error codes. If you do, that's great - it gives you a starting point. I'm no expert on Audis - I just got an A6 C6 with the 3.2 a little under a year ago, but I've taken apart and put together a few Volvos, so if that gives me any credibility, here's what I'd do;

- Check codes. Should always be first on the list.
- Check transmission and engine mounts. You might want a lift and a breaker bar for this.
- Check other possible sources of vibration. Engine is most likely alternative source in this case, since it vibrates at standstill, but even small things like loose wheel bolts or shot wheel bearings can cause weird vibration issues.

I'm guessing that the torque converter will be the first thought in many people's mind, but don't jump to conclusions. That's what gets expensive. Start small and simple, get the car on ramps or a lift, and see what's up under there.

- S

 

[Matt stone]

Thanks for the reply. I did have the engine mount selonoid fault code. I have replaced that and the fault has cleared. I've had it up on the ramps and non of the other mounts have any play other that the front snub mount which I have ordered?

Wheels have been swapped front to rear which also made no difference

 

[Sommerfeldt]

The snub mount can definitely cause vibrations under load. Volvos have the same issue with that mount (though Volvo often calls it a "torque mount"). I'd probably hold off on doing anything else until you replace that one, and see if that fixes it, especially since you had no other fault codes.

One other metric to see if there's something going on in the transmission is to monitor temperatures under load. I don't have the numbers by heart, but look up the operating temps for the transmission, hook up VCDS and see if yours is within spec.

- S

 

[BigRusko]

I had the same issue on my CVT 2.7tdi;

....vibration bad under load & at 60mph+, when stationary in P R D. OK when in neutral....

Check the inner CV joints for wear. I ended up changing the NS driveshaft and both CV joints and this solved the vibrations I was experiencing.