Whirring/grinding at low speeds = problem? Help needed

Page may contain affiliate links. Please see terms for details.

DRBC43AMG

MB Enthusiast
Joined
Mar 15, 2010
Messages
1,118
Location
Switzerland, Locarno (TI)
Car
2013 C63 AMG coupe "T-Rex", 1999 C43 AMG saloon "Grandma" (sold), Ultima Sports Can-Am (sold)
I am starting this new thread as I am at a loss to find a solution.

On my w202 240T I can hear a slight whirring noise from the front right when turning right in a bend or going around in a circle clockwise. No noise whatsoever on the left or going anticlockwise.
I posted the question and asked around. Replies and suggestions pointed to the bearings. Checked the bearings on the front right and didn't find neither wear or excessive movement. All seemed fine.
The noise continued for a couple more weeks and finally in desperation I dropped the car at the local MB dealer who checked and didn't find anything either. However, they did change the rear axle oil which wasn't really necessary as I had it done a couple of months previously in a service by my trusted independent technician.
So after getting some new spare parts, I spent my Sunday in overalls and dismantled both left and right hubs and installed new wheel bearings and races on both sides. Washed all the bits, cleaned greased and checked everything around there (hubs, backing plate, calipers). The old bearings on the left and right didn't show any abnormal wear.
I went for a test drive round the block and guess what.....? The grinding noise is still there :wallbash: I then lifted the back end and placed it on stands so that was off the ground. Switched off the electronic safety controls ESP, ASR, etc., put it in drive and..... NO NOISE :crazy: So that seems to exclude the transmission (gearbox) or prop shaft.
What could that grinding noise be
confused.gif
confused.gif
confused.gif
NEED some IDEAS before I go totally bonkers. Thanks :thumb:
 
Maybe stating the obvious here, but what about the tyres?
 
Michelins PS all round :cool:: new on the back and 40% worn on the front. They came from my C43 and didn't make any specific noise. The whirring was there before changing wheels and snow tyres last Spring
 
If the noise was coming from the front right, why did you suspect transmission noises?

Could it be the tyres rubbing somewhere inside the wheel arch on full lock? from your description, it would be rubbing at the rear of the inner arch on the flat vertical face.

I'd put it on full rh lock and then turn the engine off and try and squeeze underneath to see what is what.

I suppose it could be the outside lip of the disk rubbing too if the disks geting on a bit.
 
If the noise was coming from the front right, why did you suspect transmission noises?

Could it be the tyres rubbing somewhere inside the wheel arch on full lock? from your description, it would be rubbing at the rear of the inner arch on the flat vertical face.

I'd put it on full rh lock and then turn the engine off and try and squeeze underneath to see what is what.

I suppose it could be the outside lip of the disk rubbing too if the disks geting on a bit.



Looks like the right way to go, put the car on full lock other way, dampen wheel arch and put some talc on it.
Go for a short drive to get noise and then check if it has rubbed on inner wheel arch
 
Sorry DRBC43AMG, but I do not think that an unloaded rear suspension in drive is a realistic test for what you describe .......... inventive & daring .... but then so is a stethoscope on the inside of the rear hub at anything over 30mph. I would also check for witness marks between the rear discs and the caliper mounts, hope this helps.
 
Thanks for the ideas so far but I have to say that there is no rubbing of the tyre on the inner arch, suspension element or elsewhere.
The whirring can also be heard driving in a straight line but definitely louder turning right.
Spike, I like your suggestion of disc lip rubbing. Indeed the discs are on the way out (close to minimum thickness I guess) and are on the "to be changed" list in the not too distant future
 
You havn't got a broken spring, thats transmitting/ amplifing the road noise?
 
You havn't got a broken spring, thats transmitting/ amplifing the road noise?

No, no, I checked closely after reading about all the problems you have on your "Island", even if our roads are not very good either
 
I'd be checking suspension and steering bushes but since it's been with the dealer I'd expect them to have done that.

The fact that it only occurs on full lock might also point to the steering rack. If it's a PAS system then maybe it's noise coming from the hydraulics? I presume fluid levels are OK. Is there any leakage from the PAS system?
 
I ground the lips of the Volvo disks with an angle grinder to stop this noise as they were still within limits.

...that was 3 years ago and they are still OK.
 
I have exactly the same problem on my W124.

Had it all checked, it's all fine. but there's a slight grinding/knocking when turning the steering wheel at low speeds.

I'm really curious to see what this is.

Somebody on my previous thread stated that this could be the rubber seals on the steering column that needs repairing. How could you check for that?
 
Look at the front wheel arch liner on that side. Are there any tyre marks on it?
 
I ground the lips of the Volvo disks with an angle grinder to stop this noise as they were still within limits.

...that was 3 years ago and they are still OK.
Spike, did you have that noise on the Volvo before grinding the lip?
 
I ground the lip off because the lip was causing the grinding noise.

It cured the problem.
 
The lip is a remnant of previous wear, it serves no sensible purpose and there is no reason for error in getting rid of it, what repercussions could there be??
 
Well, decided that today would be a good moment to get to the bottom of the cause for the whirring noise. Cleaned the disc and removed all the rusty crust around the edge. Outside lip is nor very thick so left that. Cleaned with a wire brush and plenty of compressed air to remove all the dust and put everything back together. I then went out for a spin and....... the noise is still around. Grrrrrr. :wallbash: I guess I will live with it for the moment and further down the road I will change the discs and pads. If the noise remains after that, I'll consider throwing the car away :eek: (just kidding).
Anyway, thanks to all for the comments and useful suggestions. Till next time, over and out :)
 

Users who are viewing this thread

Back
Top Bottom