Very strange sound, need some advice. - BMW Forum

Vontropnats · 10-15-2006, 07:57 AM

Hey everyone, my 1993 E36 325is is making some crazy sounds while I'm moving. There is a steady train-track sounding kind of noise and it seems to be coming from my rear wheels. It's extremely loud, annoying, and something to concern myself with because I need this car to work! Unless I am at a dead stop, I hear the noise at all times. Here's a link to a sound clip of it that you can download and listen to if you feel compelled to help me.

Please help!

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Vontropnats · 10-15-2006, 01:59 PM

Is there anybody out there?

Just nod if you can hear me.

Seriously though, I really could use some advice.

thekid · 10-15-2006, 02:56 PM

not going to go through the registration process to listen to it... sorry...

But here's a question, did the sound suddenly start? Or did it slowly start to get louder? If it kinda crept up it could be wheel bearings or axle related. Is the sound speed variable?

Vontropnats · 10-15-2006, 03:12 PM

You actually don't ahve to register. In the top right area of the page it says in rather small letter "Download Now", by clicking that you get to download it without logging in or anything. Yes, the sound does have to do with speed. As I am coming to a stop, the intervals at which it occurs get longer and longer, until it stops completely when my car stops.

It also slowly started to get louder, at first it was so quiet that it didn't bother me at all, now it roars. If I really get on the gas the sound is very rapid, which also led me to believe that it was wheel-related or something of that nature.

But do try to listen to the clip, you should be able to download it by clicking in the top right. The clip really does this justice as it's very hard to explain.

thekid · 10-15-2006, 05:38 PM

kk, I just listened to it... I think it's the wheel bearing(s), but I am not 100% sure because mine never got that loud before I replaced them. If you are planning to do the work yourself, you can take off the wheel and the brake and actually see the bearing, if you can see the ball bearings (which at that volume you should be able to if it's the bearings) then that is definitely what it is. If not... could be axle or diff related, but wheel bearings would be the more common culprit. Replacing the bearings your self would be pretty hard without a press or a lift. Very high chance of knocking the car off of jackstands or a jack. However a mechanic should be able to tell you exactly what that noise is... mine (who is also a good friend of mine) rode in my car (while drunk) told me my bearings were bad before we made it to the first light out of the parking lot.

Vontropnats · 10-15-2006, 05:40 PM

Alright, my geeky friend diagnosed it as the fan clutch, but I didn't buy that from the start.

Taking my Bimmer to the shop tommorow to get this fixed! Thanks.

mmclaren · 10-15-2006, 06:55 PM

Fan Clutch at the Front will generally make a squeeking sound when its worn, but i suppose it may sound like its comming from the back end :S

thekid · 10-15-2006, 09:03 PM

Yeah it did sound more like a belt driven noise, but I ruled it out since you said it was coming from the rear... Glad you got it figured out.

Hamfisted · 10-18-2006, 01:51 PM

To me it sounds like the rear brake pads are worn out and rubbing on the rotor. How do you brake pads look?

-Mike