2007 A6 2.0 TDi SE Vibration @ 80 mph

**pooleton** · 08-03-2010,12:03 PM

Hi - I've just made the jump from BMW to Audi with a purchase of a 57 plate 2.0 Tdi A6 Avant. The car is great - soaks up the miles on the motorway and gives decent fuel economy. I have noticed though that there is a strange vibration between 75 and 85 mph (2200 - 2800 rpm). The vibration doesn't come through the steering wheel, it's the whole car that vibrates. It's more noticable since I've fitted DVD players to the headrests as they rattle quite loudly when the vibration starts. Setting the cruise to 80 and covering a fair few uninterupted miles on the motorway helped isolate the issue to having the engine under load. If the car was pulling up a slight incline or hill then the vibration was there - on a down slope the vibration disappeared - and this was all at constant speed. Has anyone else come across something similar?
Thanks.

**harvey6586** · 08-03-2010,10:51 PM

I have the same car and the only similar thing to this resulted in the rear wheels not being balanced up properly, it felt like the whole car was shaking but no feed back through steering wheel.

Worth getting them checked out, could be a cheap fix for you

**Peter D** · 10-03-2010,05:23 PM

It's the BiB knocking on the side window to get you to slow down. No, joking aside, you need to tell us the mileage. Your on lad off load may indicate a worn drive shaft or in fact an expiring Dual Mass Flywheel. Are there any other symptoms or noises. Did you buy this from a dealer with a warrantee. Regards Peter

**pooleton** · 10-03-2010,05:37 PM

Hi Peter - the car has done 28,000 miles and was purchased from a garage in Southport - associated with Halliwell Jones.
The car is still under warranty with Audi (6 months left) but I've already asked them and they tell me there's nothing wrong and they can't find an issue - typical dealership response unfortunately.
I'm going to go for a full independent wheel balance and tracking check to make sure it's not out of balance wheels since the vehicle is on its first set of tyres and they're getting low.
I've googled the issue and there are a few hits with similar issues but no definite resolution.
Thanks for your response though.
Regards
Tony

**Peter D** · 10-03-2010,05:54 PM

What gearbox is this. Did you take out there Techi and show him the effect. Can you prvide any detail to the frequency of this vibration, I'm starting to think the engine may be missing a beat, live data would be required to identify that. Regards Peter

**pooleton** · 10-03-2010,06:07 PM

Hi Peter - the box is the manual 6 speed. I left the car with them rather than take a techie out in the vehicle. I think if the balance and tracking doesn't resolve it I'll be going back to Audi and taking someone out on a road trip.
Not sure what you mean about frequency of the vibration - do you mean how often it vibrates or the rate of vibration?
Tony

**Peter D** · 10-03-2010,10:06 PM

Frequency is the rate of vibration. Does this come on gradually or is it instantaneous at a speed. Regards Peter

**pooleton** · 11-03-2010,10:20 AM

Hi Pete - the vibration is pretty much instantaneous once you hit 75-80 miles an hour. Push the car over 90 and it disappears, but obviously for legal reasons I have never done that - someone informed me that was the case.

**Peter D** · 11-03-2010,10:39 AM

The tyres/rims need careful inspection and the inner diameter of the rims measured at several angle for any rim distortion i.e. not round, tyre side walls and surface. I think you will find your problem. Regards Peter

**pooleton** · 11-03-2010,06:14 PM

Peter you were spot on. Whilst the tread depth of the rears is still up at 5 mm the drivers side rear had a split on the inner wall down to the wire. Two new tyres on order being fitted tomorrow and then a run up the motorway to test it out.

Thanks for you continued support and help on this one.

Regards

Tony