vibrations at speed

[alinghi9]

hi

just been to france and back over the long weekend, and have been able to drive a bit faster, noticed that the car has been vibrating slightly when accelerating at speeds of around 80-90mph. I get the feeling that it is coming from the back wheels, as you can feel it through the driver seat.

any suggestions what this could be and if its serious?

thanks for you help.

 

[moag]

Just noticed this on my car recently

I put new wheels on a few weeks ago so i think one of them might not be straight. Open to suggestions on other possible causes though, its only an issue at 80mph +

 

[jungleman]

i was gonna say have you have the balancing on your wheels checked?

 

[Jord]

Mines the same, think ive lost a weight on one of my wheels

 

[alinghi9]

and if its not the balancing?

 

[Harrelson]

wheel bearing? they can cause vibration and it happens at certain frequencies (certain speed zones)

 

[jungleman]

guess it could be the CV joint as well if its a front wheel issue, could be a flat spot in a wheel? am sure there are other things such as the wheel bearing as harrelson mentioned, buts its worth checking the simple & cheap things first

 

[alinghi9]

ok great will get those checked out, the balancing and wheel barrings. May i ask what the CV joint is?

jungleman - was going to ask i have upgraded my springs as you can see, but i find that the car still floats around and the ride still seems fairly harsh, is that because the audi dampers dont suit the upgrade kits?

 

[jungleman]

the CV joint is the joint that links the drive shaft to the wheel, if you have a look at your wheel it will be incased in a rubber shroud to keep it well greased and the dust & dirt out

http://www.blauparts.com/assets/audi_vw_cv_joint_live.jpg

the S-lins suspension insnt the smoothest about anyway from what ive heard, but any bouncyness/floating is because the springs & dampers arnt matched, this is a fairly common problem when you use just lowering springs without match aftermarket dampers (i have the same issue on my S3) 90% of the time the compromise even when giving it some stick is worth it unless the road is very bouncy and then the handling can feel a little bit hairy.

 

[alinghi9]

right got you on the CV joint, is that generally an expensive bit to repair/replace?

yeah i thought so with the suspension, with the roads being undulated and not smooth in terms of the compound of the tarmac you feel every little hole and the car just starts bouncing around.

any recommendations for dampers? i was looking at some koni fsd ones?

 

[jungleman]

to be honest mate got no idea as never had to change one, i cant see it being too expensive for parts & labour as its all external and should only be a few bolts etc to remove and dont think any realignment is needed after.

for audis ive not really looked at damper/spring combos as ill be going down the coilover route as i want some adjustability, but back when i had an alfa, all the GTA boys were using fsd & Eibach pro and raved about it, went out in a couple with them fitted and even in just a fwd car they stuck like s**t to a blanket and the ride quality was fantastic so i cant see you going wrong with them!

 

[marc_mcquilling]

sorry for the thread hi-jack but...

im having a similar problem but mine occurs between 55 and 65mph.

I have had it checked out by a garage as it is still under warrenty but they have struggled to find anything wrong.

what can i suggest for them to try next?