Road Noise (title change) - Beearing, CV joint, warped disc, diff??

rebel.ranter

Hi, I just switched out a seized front left brake caliper but there is still a bit of noise emanating from somewhere. It is a bit of a howl that kicks in most notably at 25-40MPH. Above this it is not as noticeable. I suspect the front left wheel bearing.
Initially I thought the noise was coming from the diff before I spotted the seized caliper. The reason I am now suspecting the noise is from the front bearing is because the noise doesn't change if I slip the car into neutral. Is it reasonable to make this assumption? Or could a noise from the differential stay the same in & out of gear? I am hoping it's not the diff.
Could a seized caliper "cook" a wheel bearing? The disc is very discoloured & the were signs of white heat marks on the caliper.


Car: 1996 BMW 320iC

I plan to book it in some place as soon as I can but would like to get some opinions.

EDIT:
Went for a drive with me in the back seat, a definite sound from the rear left, specifically coming from the area between the rear wheel & the diff.

DiarmaidGNR

rebel.ranter wrote: »

Hi, I just switched out a seized front left brake caliper but there is still a bit of noise emanating from somewhere. It is a bit of a howl that kicks in most notably at 25-40MPH. Above this it is not as noticeable. I suspect the front left wheel bearing.
Initially I thought the noise was coming from the diff before I spotted the seized caliper. The reason I am now suspecting the noise is from the front bearing is because the noise doesn't change if I slip the car into neutral. Is it reasonable to make this assumption? Or could a noise from the differential stay the same in & out of gear? I am hoping it's not the diff.
Could a seized caliper "cook" a wheel bearing? The disc is very discoloured & the were signs of white heat marks on the caliper.


Car: 1996 BMW 320iC

I plan to book it in some place as soon as I can but would like to get some opinions.

From the sounds of it your diagnosis seems bang on.
Change the bearing anyway (cheap fix) and if the problem remains it might be the diff.

rebel.ranter

Thanks for the response. I can't pinpoint exactly where the noise is coming from, sometimes I think it's the rear, then I switch to thinking it's the front.
Really confusing. I'm hoping it's the bearing. I changed the diff oil last night but there is no change in the noise, not that I was expecting a massive difference, just ticking off a cheap option.

DiarmaidGNR

rebel.ranter wrote: »

Thanks for the response. I can't pinpoint exactly where the noise is coming from, sometimes I think it's the rear, then I switch to thinking it's the front.
Really confusing. I'm hoping it's the bearing. I changed the diff oil last night but there is no change in the noise, not that I was expecting a massive difference, just ticking off a cheap option.

I'd say it is the bearing, the pressure that would have been put on it if you were driving with a sticking caliper would have been a heck of a lot.
Put the car up on a jack and compare the two front wheels by spinning the two of them and comparing feel and noise. You might notice a difference in the two.
Also, - did the noise start after the problem with the caliper?

rebel.ranter

DiarmaidGNR wrote: »

did the noise start after the problem with the caliper?

Herself drives the car but I do all the maintenance & cleaning. I noticed that the side of the car was producing more brake dust then the driver's side. She mentioned to me recently that there was a noise that had started. So in short, yes the noise seems to coincide with the caliper seizing. I think the seizing had just gotten worse in the last week.

DiarmaidGNR

rebel.ranter wrote: »

Herself drives the car but I do all the maintenance & cleaning. I noticed that the side of the car was producing more brake dust then the driver's side. She mentioned to me recently that there was a noise that had started. So in short, yes the noise seems to coincide with the caliper seizing. I think the seizing had just gotten worse in the last week.

I'd go ahead and change the bearing so.- It's bound to be it.

I think you have to change them in pairs (like with break pads, shocks, tyres etc.) - but not too sure.

rebel.ranter

I had a rear one changed about a year ago, I don't think there is a need to do both sides.
I will be changing both front discs & pads though as the passenger side ones are well & truly cooked!

Owen

Does the noise increase in pitch as you accelerate?

DiarmaidGNR

rebel.ranter wrote: »

I had a rear one changed about a year ago, I don't think there is a need to do both sides.
I will be changing both front discs & pads though as the passenger side ones are well & truly cooked!

Good luck with the bill!

Owen

RR usually does his own labour

rebel.ranter

PaintDoctor wrote: »

Does the noise increase in pitch as you accelerate?

Not really, it is most noticeable 25-40mph, after that it is less noticeable. You're right I do most of my own labour but I hate bearings! I've done them on an old Beetle but not for a long time!
Not sure if I have the time to tackle a diff if that's what ends up being wrong. I've nowhere to put the car these days, the garage I use is currently full of insulation! I'll do the discs & pads on the driveway though, crazy paying labour for such an easy job (unless it's raining;)).

Owen

Normally a wheel bearing will be a drone that increases in pitch as you get faster, but there's not much else that could be causing it assuming the brake caliper is mounted securely, the back of the pads are copper greased, and the anti rattle clip's in place if your caliper has one.

peasant

rebel.ranter wrote: »

Could a seized caliper "cook" a wheel bearing? The disc is very discoloured & the were signs of white heat marks on the caliper.

It could indeed. Bearings are greased and sealed.
Subject them to great heat and the grease will boil off, disappear through the seal and the bearing will run dry...grinding metal on metal, end of bearing

rebel.ranter

When the rear wheel bearing started to go you could tell very clearly which side it was coming from when you turned at speed, it got louder when you turned to the opposite side. With this there doesn't seem to be the same effect.
I'm not sure if it should be the same.
As for it increasing in noise, at higher speeds it could possibly be drowned out by the exhaust, it is a convertible (with the hard top on) so exterior noises seem louder.

rebel.ranter

Right, on further investigation I have ruled out a failed front bearing as the noise I am hearing is definitely coming from the rear of the car. I sat in the back while the car was being driven & I could definitely hear a noise emanating from the rear left side.
I had the wheel bearing replaced on this side 20k miles ago & at that time it was an easy diagnosis. This time around it seems as if the noise is coming from the area between the wheel & the diff on the left hand side.
I am suspecting an issue with the CV joints on the half shaft at this side. Anyone else have an issue with a half shaft/CV joint on a RWD car?

rebel.ranter

Just to update, the noise was indeed a failed bearing....at the rear. What made it worse was it was one I had replaced in July 2007. It was one of the few occasions that I bought a spurious part (well the garage that fitted it did). I got a genuine part this time so all should be good for a while.

Thankfully it was not the diff!

DublinDilbert

I replaced 2 rear wheel bearings on an E36 before, with ones from GSF and both failed within 20K. When i went back and got new ones they were a different brand, never had any problems after that.