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Lee
Lee, BMW Technician
Category: BMW
Satisfied Customers: 366
Experience:  BMW STEP Custom Training, Cert. BMW Diag. Tech, ASE Master
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only in reverse my car is making a grinding squeaky noise

Customer Question

only in reverse my car is making a grinding squeaky noise
Submitted: 5 years ago.
Category: BMW
Expert:  Lee replied 5 years ago.
Hello welcome to JustAnswer,

The other Experts and I are working on your answer. As you may know it is very difficult to diagnose any sort of noise without being able to hear it. I just have a few questions for you.

You say it is a grinding squeaky sound, can you describe it any better? Is it a constant noise that doesn't go away?

Does the noise occur when pressing the brakes, or coasting in reverse, or while just shifted in reverse with the vehicle stopped?

Can you tell where the noise is most present at? (The left or right front or rear, engine compartment, etc)

If you wouldn't mind describing in as much detail as you can, I could try to narrow it down some and give you some better suggestions
Thank You.
Customer: replied 5 years ago.
the noise is only in reverse and does get louder when coasting as opposed to pressure on the breaks. The noise sounds like its coming from under the center of the car, but that could be just from my position in the driver seat.
Expert:  Lee replied 5 years ago.

Is it a constant squeaking that doesn't go away or more of of several squeaks spread out?
Customer: replied 5 years ago.
constant...sounds like metal grinding...once i put the car into drive, it goes away. it happens as i back out of my garage
Expert:  Lee replied 5 years ago.
Hmmm, nothing solid is really coming to mind for what you are describing. There could be a few different things causing this, but I I will opt out and allow another expert to chime in if they have experienced it and feel they can help.
Thanks
Customer: replied 5 years ago.

i've been told it could be a brake caliper rubbing or the transmission going...any thoughts?

Expert:  Lee replied 5 years ago.
Since it is only occuring in reverse, it could be something internal in the transmission, it could be something in the driveline, or it could be as simple as a brake rotor backing plate rubbing.

Usually if it was worn brakes, you would notice it more when pressing the brake pedal.

I have not personally experienced a constant metal on metal grinding noise like this that only occurs when coasting in reverse, and goes away when shifting back into drive. I would suggest safely lifting the vehicle up on jackstands if it is RWD, and operating the vehicle in reverse to see if you can pinpoint where the noise is coming from.

I'm sorry I could not be of more assistance. Your question is opened up to all other experts to read and respond to if they feel they can give you a more specific answer.
Thanks
Lee, BMW Technician
Category: BMW
Satisfied Customers: 366
Experience: BMW STEP Custom Training, Cert. BMW Diag. Tech, ASE Master
Lee and 2 other BMW Specialists are ready to help you
Customer: replied 5 years ago.
Thanks for trying
Expert:  Kenny replied 5 years ago.
I have seen this before and it is from the E-brake assembly inside the rear brake disc. When in reverse it shifts everything and causes it to rub but forward everything shifts out of the way. It will get worse and I have seen it lock the wheel right up. You will need new e-brake shoes and hardware and brake discs and might as well replace the pads as well seeing how they will be off.