Metal scratching sound coming from rear wheel

[Mr-Goose]

I've had my 2012 E350 Coupe about three or four weeks. I have a sound coming from the rear passenger side wheel. I generally can only hear it when driving at fairly low speeds. At first I though a rogue bit of bodywork was loose and rubbing against the wheel. I've had a look and can't see anything. I called up my local MB dealer and have it booked it in three weeks time.

Since calling them up earlier today it now sounds somewhat worse so I will be calling back in the morning and trying to get it looked at ASAP. The sound is intermittent but regular. There is nothing loose around the wheel and the wheel itself is not loose. The metal surround behind the brake disc was fairly close to the brake so I push it back but still the noise persists. I don't think it is the suspension.

I do wonder if it is the hand brake. It is an automatic and when I stop I press the brake peddle, put the gear stick in P and press down the handbrake foot peddle. When I let go of the brake peddle the car still moves a tiny amount and to me feels like the gearbox P is stopping it rather than the handbrake. I've never really owned an automatic before so am not sure how the handbrake should work. Should it stop the wheels moving 100%? I presume so. I can rock it gently back and forth (ever so slightly) just by turning the rear wheel by hand. What part of the handbrake mechanism actually stops the wheel? Is it one of the normal callipers? When I apply the brakes normally while driving they operate correctly without and abnormal noise.

Any ideas?

 

[MikeInWimbledon]

Kwikfit ?

Given all you've said, it might make sense to just take the car into a large (not normal) Kwikfit outlet and ask them to do a (usually free) safety check.

From what you have said my suspicion is that a brake is still catching, or that a wheel may be slightly loose (i.e. not properly bolted on)

There are more complicated possibilities, but at the very least, start there.

 

[Heathy71]

It could be the back plates rubbing on rust buildup on the discs, mine does it fometimes and it's really annoying! My c class also moves a little after putting the handbrake on.

 

[Mr-Goose]

Thanks. Looked up backplate rubbing and one video mentioned the possibility of a stone caught in between the plate and brake. The noise certainly sounds similar. I think I will try a brake inspection if MB can't look at it today.

 

[optimusprime]

My problem was aftrer going over a gravel road , a small stone was thrown up and it went down inside the back plate and the disc. The brake caliper was holding it in there and would never have got out Only found this after i removed the wheel and looked down through the caliper and disc ..Good luck, i hope it was simple as mine was .

 

[Mr-Goose]

I called MB today and they couldn't move my appointment forward so I headed in to town to try kwik fit. On route I had a loud contestant ticking noise that matched the rotation of the wheel and when I turned left I had a loud screeching noise. Due to this I stopped at the first garage on route. They didn't remove the wheels but they had a good look around and found nothing loose. He took it for a short drive and concluded it might be the drive shaft wearing out and suggested it went to MB.

I popped in to the local MB deal next and the sound disappeared on route. One of the mechanics/technicians was good enough to take the car for a drive round the block a couple of times. There was no noise. He was fairly certain that it was a stone caught between the backplate and brake disc. He performed a couple of emergency stops to try and clear it. He was sure it wasn't anything major. I'm going to see how it goes. I have a small inspection camera so will try to have a look between the disc and plate.

 

[optimusprime]

You never know then , i may have been righ.

 

[Aletank]

If it's the same parking brake system as my old W203, handbrake shoes with springs etc, I had this sound, couldn't see anything visible with the wheel off etc but it turned out to be a snapped handbrake shoe spring, that was trailing on the disc giving the noise.
Once you get the brake disc off, you should see. Think I was charged about £40 for the investigation and new spring fitted at a local garage.

 

[Mr-Goose]

I think I found the cause of the noise.

Update:

The grinding noise has mostly gone except for one very brief occurrence yesterday. However, I have instead had a rattle when driving between 10 and 20 mph.

Decided to have another look this morning. I poked the little inspection camera between the backplate and brake pad but found nothing. I banged all the bits underneath. Nothing. I was just just about to give up when I ran the handle of the wrench over the backplate and it made the same sounding noise. The other side did not. It sounded as though the backplate was not completely secure. Had another look under the car behind the wheel with more light. Finally spotted a loose bolt. It is right next to the axel and has been rubbing against the axel to the extent that the bolt head and axel now both have a chamfer. I can just about get a finger tip to it but not enough to turn it.

Phoned MB and even with explaining that there is a loose bolt rubbing against the axel I had to fight to get an appointment on Tuesday to get it looked at.

You can just make out the worn out bolt head and axel in this pic.



Feeling much better now I've found the problem as it was driving me crazy.

 

[optimusprime]

Thats the drive shaft in the picture ..Is that bolt holding on the back plate ?.

 

[Mr-Goose]

I don't honestly know. It's not a very big bolt so I doubt it is holding anything significant.

 

[Ponton-Jetronic]

Check the shoes also which are inside the disc hub - disc must be removed first. as in '85 to '95 model incl W124

 

[Mr-Goose]

Well my car went in today to sort out the loose bolt. I was told it was fixed (everything tightened and lubricated where appropriate) and they took it for a test drive. I picked it up and on the way home I could hear the same rattle and when I got home I checked the bolt and it was still loose.

It's going back in the morning with printed photos showing where the bolt is located.


At least it got a wash. Will see if I can't get a free MB mug out of them

 

[reflexboy]

Aren't main dealers just the pitts!! Due to bad experiences I'm really anti them

 

[Mr-Goose]

Well my car went in and eventually they phoned to say they found the bolt but it will take 5 hours to fix as they need to take it all apart. They have arranged a hire car for a few days as they are busy.

I now have a 66 plate s350 on my drive. It's huge!!! I took it out for a quick spin. It is without doubt the most comfortable seat I have ever sat in, anywhere. But the rest of the car on the inside doesn't do it for me. It's too big.

 

[AntG350e]

I had this today on my c350e - By the time i'd rationalised and composed my thoughts the issue just didn't make any sense. So, i popped the front wheel off where the offending noise was coming from (front offside, but could have been any corner).

We have a 10mm chipping drive way and one of the little blighters had trapped behind the brake disc and the shield behind. Leveraged it out with a suitable screw driver and hey presto. Issue resolved.

 

[optimusprime]

Ant a well known problem that comes after driving over shale, or any loose serface .Ask me why ha ha

 

[AntG350e]

I am so relieved - And regretting having a chipping drive!

 

[optimusprime]

Ant only hapened to me once in 50 years .Thats how i klnow about it .I was on my way home from a stint of night fishing on the River Severn at Worcestershire Got half way home at 3,30 am and this screeching noise came on . I put up with it til the next day ,,then i found it ..

 

[Rodker]

I'm finding a noise like I'm dragging chains between nearside door and front wheel arch on my clk350 07 auto when idling or moving. Can see nothing. Any ideas,thanks loud metallic tinkling.