Constant squeal from front/driver's side wheel?

[MATT0404]

I'm hoping to find some help here. I picked up my 540i/6 a couple of weeks ago. On the way home I noticed a squealing/squeaking sound coming from the front, driver's side wheel. I gave it a little time to see if it would clear up on it's own, but the sound persists.

The sound starts anywhere above 5-10 mph, and stays constant after that. The sound does stop when the brakes are applied. This leads me to believe that it is brake related, but the front pads and rotors are new.

I removed both wheels and inspected the brake components, but everything looks fine. Any suggestions would be greatly appreciated.

Thanks,
Matt

[mattmartindrift]

stone in the caliper or sheild behind the rotor?

what's the pad life look like?

[bimmerfiver]

Brakes or wheel bearing. I'd re-do the brakes on that side after I eliminated the wheel bearing.

[MATT0404]

stone in the caliper or sheild behind the rotor?

what's the pad life look like?

The pads and rotors look new.

I took the wheel off and did a visual inspection of the brake components and didn't see any rocks. I'll go disassemble the brakes and reassemble them to see if there's anything internal that I missed.

Brakes or wheel bearing. I'd re-do the brakes on that side after I eliminated the wheel bearing.

I'm thinking brakes. I tested the wheel for play and it was tight in all directions.

[e39dream]

check for rocks first, that's free so long as you do your own wrenching. then proceed to bimmerfiver's suggestions.

[MATT0404]

Thanks for your help, guys, as of now the problem is SOLVED! I'm just back from removing and reinstalling the caliper and pads. There was nothing wrong with the rotors/pads/calipers, the problem seemed to lie with the brake pad sensor. It was loose and looked really worn. I pulled it out and zip tied it out of the way, Brake-kleen'd everything, checked for rocks, loose dust shield, etc., and reinstalled everything. I went for a drive, expecting the brake light to come on since I removed the sensor, and there was no squealing. Oddly enough, though, there was no brake light either.

I'll check back if the problem returns. Thanks again!

[e39dream]

I don't use the pad wear sensor system, I like to check my own pads. All you have to do is cut the sensor side of it off and solder the 2 wires together and the light will never come on again. I am used to listening for the squealies.

[Hogg]

I can't see how the wheel sensor would have caused a squeeling sound.

I wonder if this was a dirty and partially stuck caliper that was causing the brake pad to slightly touch/rub and cause the squeal. And you accidentally fixed it (for now) when moving everything around and cleaning it all up. If it comes back in a few days then that might be something to check for.

[MATT0404]

I can't see how the wheel sensor would have caused a squeeling sound.

I wonder if this was a dirty and partially stuck caliper that was causing the brake pad to slightly touch/rub and cause the squeal. And you accidentally fixed it (for now) when moving everything around and cleaning it all up. If it comes back in a few days then that might be something to check for.

Haha, you're absolutely right. The squealing is back. I guess I'm going to have to do a more thorough inspection, though I'm not sure where to go from here. Hopefully I get some time tomorrow to work on it.

[Hogg]

Here's a few things to try to help narrow it down. I'm not speaking from any point of knowledge about your issue, just applying sound engineering practices:
1. Does it happen when going straight, turning left and turning right? Or does it only happen on one of those? Or does it happen on all three but less on some.
2. Drive backwards at 10mph - does the sound happen when going backwards?
3. For the brakes making the noise go away, when exactly does it go away? For example if you lightly touch the brakes does it disappear immediately? Or do you need to apply the brakes harder to make it disappear? Does it seem like its the application of the brakes (very light braking) or the forward pressure on the components as you brake that is causing the squealing to disappear?
4. Is the squeaking sound constant or rhythmic? If its rhythmic does the frequency of the noise go up (time between squeaks gets less and less) as the car speed goes up?
5. Does the squeaking sound increase in volume or change in pitch as the car goes faster and faster
6. Are you sure its the wheel and not the engine. Put the car in Neutral and rev the engine slowly past 5000 rpm - is the squeaking present.
7. Jack the car up with the wheel off the ground and spin the wheel by hand - does it squeal.


Let us all know what you find from any and all tests and maybe someone will have an idea....

[NJe39]

Haha, you're absolutely right. The squealing is back. I guess I'm going to have to do a more thorough inspection, though I'm not sure where to go from here. Hopefully I get some time tomorrow to work on it.

MAtt..what did you do to get this issue resolved? Thanks

[cal45fan]

stone in the caliper or sheild behind the rotor?

This happened to me and I thought my wheel bearings went out! It sounded like a wrrrring noise. Scared the piss out of me.

[MATT0404]

Sorry for not following up with this thread. I solved the problem by removing and reinstalling the caliper/rotor, wire brushing any surface rust, and reapplying anti-squeal to the brake pads. After torquing everything down to spec there was no more squealing. I'm thinking something was loose or improperly seated.

[Aintfirsturlast]

Sorry for not following up with this thread. I solved the problem by removing and reinstalling the caliper/rotor, wire brushing any surface rust, and reapplying anti-squeal to the brake pads. After torquing everything down to spec there was no more squealing. I'm thinking something was loose or improperly seated.

I had the same problem. My fix was the same; however, only lasted two months.

[e46black]

Sorry for not following up with this thread. I solved the problem by removing and reinstalling the caliper/rotor, wire brushing any surface rust, and reapplying anti-squeal to the brake pads. After torquing everything down to spec there was no more squealing. I'm thinking something was loose or improperly seated.

my 03 540i/6 has the same symptoms
I took caliper apart, changed piston seal, guide pin rubber, lubed all moving parts, flushed the brake fluid and the noise went away for 2 months.
then it came back.
I also realized, that everytime I jacked the car up (release the suspension tension), the noise would go away for like 50 miles.

thanks in advance for any help

[ViolinARC]

my 03 540i/6 has the same symptoms
I took caliper apart, changed piston seal, guide pin rubber, lubed all moving parts, flushed the brake fluid and the noise went away for 2 months.
then it came back.
I also realized, that everytime I jacked the car up (release the suspension tension), the noise would go away for like 50 miles.

thanks in advance for any help

I know it's an ancient thread and I really don't see a resolution here. This symptom sounds much like a failed front wheel bearing and since the entire hub by Timken is in the $110 range, it seems like an inexpensive possible solution (although the task of replacing is daunting). I replaced mine because of tramlining and odd behavior in sharp turns. Issue solved...

[crusadercc]

Did you ever solve your problem? I've got the exact same thing. Had the tires rotated (i.e. jacked up) and the squeaking went away for a few days. Now (weeks later) it's back with a vengeance. I replaced the pads and rotors myself a few months back, but the noise was happening before and after that. I suppose it could be the wheel bearing but I thought they only made a growling noise when failing.

[crusadercc]

I'll answer my own question. I took my car to my local independent mechanic who suggested an aggressive bedding in of the brakes was needed. He took it up to 80+ mph, then applied very strong brake pressure (right before ABS kicks in) almost to a stop. Then drive gently for a few minutes to get them to cool down, then repeat process. He says he did that 5-6 times, three days in a row. And that seemed to fix it! I've had my car back for a week and there's no more noise.