A4 Quattro Sport Rear Wheels Making Strange Noise

**Adam A41.8T** · 21-05-2009,10:15 AM

OK cool. I htink the more I read that thread I think it must be something to do with that.
If you are booking yours in now then I will sit and wait to find out the bad news!!

I will get mine looked at next week! Hopefully it will not be something too expensive. What are your thoughts on cost?

**randall977** · 21-05-2009,02:37 PM

Well I've had the car looked at by an Audi specialist (who are reputable) and they say the rear bushes are not cracked - in fact I looked as well and they're fine so I'm not sure why Audi told me they were cracked. They also had a good look at everything suspension related and found no problems. They then turned thier attention to the engine mounts and adjusted one...it made no difference! So I'm afraid the answer is not clear yet but suspension may not be the answer. I would be interested to look into the rear differential as a source of knocking but I don't know much about it...

Could still be a CV...

Cost incurred so far - £0 for inspection + mount adjustment. £130 for drive shafts (not fitted).

**Adam A41.8T** · 21-05-2009,02:55 PM

That is quite interesting then. Did they drive the car at all to hear the noise for themselves?

I must admit, I have looked through some previous service notes from Audi and they advise that the rear anti roll bar is corroded. It is only a advice though and when I look myself it appears to be only part of the casing so I cant see that this is causing the problem.

CV joint is a possibility then? I could do with finding out because it is starting to annoy me. Does yours make any difference if you pull away really slowly as opposed to at a normal speed?

**randall977** · 21-05-2009,03:52 PM

Of course when they drove the car they couldn't hear it! I've found that if I pull off at a slight angle in either direction the knocking is louder... This could mean it's putting more pressure on a suspension joint or a CV joint. If I accelerate very hard I don't think it does it. If I roll down a hill with no acceleration it doesn't do it. Starting on an incline will make it happen. I can't be sure it's the front... CV or diff is what I'm going to look at - see if you can find any threads of 4WD differential problems.

**randall977** · 21-05-2009,04:16 PM

Check out these - they'll give you a horrible feeling inside!

https://www.vwaudiforum.co.uk/forum/s...t=differential

https://www.vwaudiforum.co.uk/forum/s...t=differential

https://www.vwaudiforum.co.uk/forum/s...highlight=diff

https://www.vwaudiforum.co.uk/forum/s...highlight=diff

**Adam A41.8T** · 21-05-2009,04:33 PM

Dont like the sound of those!! I think we are looking a bit more into than we should be though. After reading those they report a clanging noise and stuff which isnt the case with mine! I am going to go out into the car park at work and try my car now just to see what happens. I will report back shortly!

**randall977** · 21-05-2009,05:49 PM

Actually the engine mount adjustment has cured the problem by 95%. It still does it a bit when pulling off up a hill but not as bad. This is just after one 30 minute journey mind you but it's my regular journey home. Are you sure it's rear?

**Adam A41.8T** · 21-05-2009,07:13 PM

OK I give up. I cant for the life of me get it to make the noise!! I wonder if it was because it was stood for a couple of months before I bought it?

**randall977** · 24-05-2009,11:25 PM

No still does it! Today I got the car to make the knocking noise really badly - I found that driving the car slowly (in first gear or second) up a fairly steep hill makes it knock badly. I'm thinking again that it could be a diff problem as I think it relates to the 4WD system kicking in (under load) and the drive shaft does rotate with the revolution of the wheels. It sounds like the front to me but there is a front and rear diff so your could be rear...

**Dave Gee** · 25-05-2009,01:01 PM

I have a similar problem with my Avant Quattro 2.4TDI, when slowly pulling away the car starts 'thumping', and can be heard / felt more in the rear. Above say 10 mph it seems to clear and run normally.
At last MOT it had a badly shredded tyre on the inside tread down to the canvas, but cannot remember which wheel the tyre was on, could this be significant?
Tyres changed/balanced but the 'thumping ' sensation has returned, like driving over rumble strips !
Any further ideas?
Dave