[Faltzer]

Hi all,

I'm curious if any other M8 owners have experienced the same issue I'm encountering and whether it's normal or not. At low speeds when pressing and releasing the gas pedal, I hear a click sound from around the rear passenger wheel like a ping pong ball which happens once when pressing the throttle, and again when releasing.

I tried searching the forums and found these threads that describe the same issue I'm facing:
https://x3.xbimmers.com/forums/showthread.php?t=1837347
https://x3.xbimmers.com/forums/showthread.php?t=1751422

I found the service bulletin mentioned in that thread for "DRIVELINE CLICKING/KNOCKING NOISE ON LOAD REVERSAL" but it doesn't list the M8.

Has anyone else experienced this with their M8? Fortunately I'm still under warranty, but figured I'd check to see if this is normal behavior before bringing it into the dealer to have it checked out.

[KillerBlackRhino]

Low speeds?

[Faltzer]

Yes, I’d say it’s most noticeable anywhere from 5 - 30 mph. It doesn’t seem to happen anymore above that (or maybe I just don’t notice it.

[ChiefM]

Is the sound primarily when the gas pedal is released? When pressing and releasing gas pedal, all drive train components get loaded and then uploaded. For this sort of fault my go to is drive shaft coupling, motor mounts, transfer case and rear diff mounts, basically, anything that can move independently of the chassis if bushing are worn. If they all check out, rear diff, transfer case or front diff usually end up being the culprit.

[Faltzer]

Update in case anyone else starts hearing similar noises:

After leaving the car at a dealer for a week to diagnose the issue, my service advisor called today saying the rear differential needs to be replaced. They didn’t have any more details to give me, just that it’ll take another week to get the parts and do the repair (all covered under warranty).

[ChiefM]

Originally Posted by Faltzer

Update in case anyone else starts hearing similar noises:

After leaving the car at a dealer for a week to diagnose the issue, my service advisor called today saying the rear differential needs to be replaced. They didn’t have any more details to give me, just that it’ll take another week to get the parts and do the repair (all covered under warranty).

Good thing it’s covered under warranty. This is one of the cases where I hate being right. There was a time when odd noises on vehicles was bushing related more times then not. Unfortunately I have found that in late model vehicles of all brands, these kind of noises tend to be major component failure.

[RJC-1]

Originally Posted by Faltzer

Update in case anyone else starts hearing similar noises:

After leaving the car at a dealer for a week to diagnose the issue, my service advisor called today saying the rear differential needs to be replaced. They didn’t have any more details to give me, just that it’ll take another week to get the parts and do the repair (all covered under warranty).

Was the issue when car is cold or full op temp?
Was the clicking constant or only each time you pressed/released the accelerator?

[Faltzer]

I first noticed it at full operating temperature, but after a couple weeks could hear it when the car was cold too. I drove the technician around to reproduce the sound and we both immediately heard it a few seconds after moving.

It was only audible when pressing and releasing the gas pedal enough for the car to shift weight back and forth, not a constant clicking. Although I did hear the noise one time as I was getting out of the driver’s seat.

[M8Bimmer]

Maybe the clicking is Blooze-manAZ cleaning his gun in the trunk. Spinning the cylinder slowly like Clint Eastwood in a spaghetti western.

[TrecNY]

Originally Posted by Faltzer

Hi all,

I'm curious if any other M8 owners have experienced the same issue I'm encountering and whether it's normal or not. At low speeds when pressing and releasing the gas pedal, I hear a click sound from around the rear passenger wheel like a ping pong ball which happens once when pressing the throttle, and again when releasing.

I tried searching the forums and found these threads that describe the same issue I'm facing:
https://x3.xbimmers.com/forums/showthread.php?t=1837347
https://x3.xbimmers.com/forums/showthread.php?t=1751422

I found the service bulletin mentioned in that thread for "DRIVELINE CLICKING/KNOCKING NOISE ON LOAD REVERSAL" but it doesn't list the M8.

Has anyone else experienced this with their M8? Fortunately I'm still under warranty, but figured I'd check to see if this is normal behavior before bringing it into the dealer to have it checked out.

I was driving around the other day with the music down and whenever I lifted off the gas pedal, I started hearing a soft chirp coming from back seat, almost like a quiet cricket. I am curious if this is what yours sounded like (like a chirp) and how loud the sound was in your car?

Just to ensure I wasn't going crazy, a buddy of mine listened and he heard the same thing. Either way, I am going to need to call BMW this weekend.... sucks, I only picked the car up a few weeks ago by doing a lease assumption. The previous owner confirmed they have never heard the sound, and to be honest, I haven't heard it at any other time other than it starting the other day

[Faltzer]

With the windows up and music off, mine was more of a thunk from the inside. With the windows rolled down, the sound outside was more of a hollow clicking. Kind of like the sound from clicking your tongue off the roof of your mouth.

[TrecNY]

Originally Posted by Faltzer

With the windows up and music off, mine was more of a thunk from the inside. With the windows rolled down, the sound outside was more of a hollow clicking. Kind of like the sound from clicking your tongue off the roof of your mouth.

Thanks. That sounds like the same issue my buddy had in his M5 - a thunk when he let off the gas or brake pedal. Which ended up being the rear differential needing to be replaced as well. I heard the noise coming from his car and its nothing like what I am experiencing. Although the hollow clicking noise you describe from outside the car does sound a bit more relatable. I'm going to bring up the differential issue to BMW and even see if I can get a mechanic to take a ride with me to verify what the noise is (hopefully).
Thanks again for the insight, appreciate it.

[TrecNY]

Update- my issue was also the rear diff. Metal shavings were found in the sample they took. BMW is going to replace the whole thing.
If you hear a soft knocking or chirp sound coming from the rear of the car or from under the rear seats, definitely recommend that you have a dealer check it out.

Ugh, now the wait begins to get my car back. In the meantime they gave me a 330, which feels slightly different than the M8