Vibration - Feels like driving over bumpy road

[Blue_Thunder]

Had a scan through the various vibration issues (ooh err), but none seem to match mine.

Noticed around a week ago that whilst driving on a completely smooth road, it feels like the car is going over bumpy ground, ie: up and down rather than side to side.

Took the car to the place I had 4-wheel alignment done about 6 weeks ago and got them to check the wheel balance. One of the rears had lost some of it's weights, so it was way out.

Got both rear wheels balanced, but the vibes are still there. I didn't get the front done as I was short of time, and I also have no vibration through the steering wheel.

It's most noticeable between 30-45 mph. Not hearing any new noises and the guys at the garage had no trouble spinning the wheels when they lifted the car, so I think a knackered wheel bearing would have possible shown itself there?

I might be dreaming here, but i'm sure it's more noticeable when i'm accelerating gently in 3rd/4th gear. There is still some vibration when just coasting.

Has anyone else experienced this before?

[Blue_Thunder]

ps. Also checked for any tyre defects but they were fine.

[oliew]

Bent alloy i would think, mines the same on the rear, i had it on the front after hitting a huge pot hole! now on the back i just feel it vibrating all the time, it dissapears nearly around 70 +
I got it balanced and they said it was balanced fine.. but you can literally see the bend in the wheel itself... oh well
anyone got a 19" RS6 alloy???

[Blue_Thunder]

Didn't notice any when the rears were on the balancing machine yesterday. Guess it could be one of the fronts, but as mentioned, the steering wheel doesn't shake.

What am I looking out for? A flat spot, or a bend inwards/outwards?

[oliew]

my wheel doesnt shake either.. but u can feel it most of the time through the car, the pothole bent the inside of the rim towards the middle prob about 2cm, and also bent slightly on the outside u can see the small flat spot in the rim. The tyre went down!!! i took a pic forget where i saved it now, but the pothole was so bad i reported it, it was literally 5" deep with a 90 degree face where u would fall in and come out again.
I could see mine on the balancer all over the place!!! i would like to drive behind mine and look at the wheel to see if i can see it wobbling.

[Blue_Thunder]

That's settled then, back to the place to check the balance on the fronts tomorrow!!

Thanks



Anyone got any recommendations on alloy wheel repairers?

[Blue_Thunder]

Well, had the front wheels balanced today. None of the wheels are deformed.

The guy at the alignment place says it's quite likely that it's because I have two different brands of tyres on the front axle.
Now I know that's not a recommended thing to have, but I punctured one of my tyres when they'd all done approx 200 miles from new and I couldn't get a matching replacement. Kwik-<beep> charged £120 for the cheapest piece of crap tyre they had, and there was no way I was going to buy a pair of them at that price!

Could a different tyre tread really cause this?

[JonnyX]

Try somebody else's wheels. If the problem persists get your front wheel bearings replaced.

[MCB]

Have you checked your springs and shocks?

[Blue_Thunder]

Try somebody else's wheels. If the problem persists get your front wheel bearings replaced.

If anyone fancies a wheel swapping party... i'm there! I'm a bit limited because i've got the RS6 brake setup, so not many people have wheels with sufficient clearance.

Stigter has just got hold of some new wheels and he lives close, I might see if he wants beer in lieu of wheels for a short period.

Have you checked your springs and shocks?

Only fitted satanschild's old coilovers a few hundred miles ago. They were second hand, but hadn't done many miles.

[MCB]

If you were to coast down a smooth road at 30-45MPH would it still do it? I.E. try to separate drive line issues from suspension.

[Blue_Thunder]

Yes, it was doing, although perhaps not quite as much as when slowly accelerating. It was difficult to tell as it's a fairly subtle 'bumping'.

I'll know for sure by the time I get home tonight. The road from place I was at this lunch time back to work is like a Landrover proving ground!

[Stigter]

Dude its the tyres. Yeah sure just let me know when you want to try the wheels.