Anybody else's M5 whine like a supercharger?

[M5Rick]

^ Good vid

[lucid21]

Originally Posted by autoxautox

That’s the thing, it does have a tensioner, it is the main pulley. It has a u shaped middle so that when the arrow is facing the ac it lets the tension off and the belt comes right off. Then as you turn the crank back so the arrow faces away it tensions it back up, then you put the four bolts back on. It’s a pretty smart design.

I found pics at the very end of this video:
https://m.youtube.com/watch?v=mNb6xTwKYHw

OK, but I don't think this is necessary and seems like a lot of work in a tight space to pull off. My understanding is that these belts will "stretch" to some degree without being damaged and a tool like this will do that for you without the need to "relieve" the tension on the belt. https://www.amazon.com/dp/B00AC60VEC...roduct_details

I've seen several videos of that being done on S63 engines, but I haven't done it myself.

[autoxautox]

Originally Posted by lucid21

OK, but I don't think this is necessary and seems like a lot of work in a tight space to pull off. My understanding is that these belts will "stretch" to some degree without being damaged and a tool like this will do that for you without the need to "relieve" the tension on the belt. https://www.amazon.com/dp/B00AC60VEC...roduct_details

I've seen several videos of that being done on S63 engines, but I haven't done it myself.

Cool tool. Thanks for the info, never heard of it.

[lucid21]

Originally Posted by autoxautox

Cool tool. Thanks for the info, never heard of it.

I'll keep you posted on if/how that tool works. Also, did you need access from the bottom, or could you take care of it from above? Trying to figure out if I should have the car on a ramp before I start. Thanks.

[autoxautox]

Originally Posted by lucid21

I'll keep you posted on if/how that tool works. Also, did you need access from the bottom, or could you take care of it from above? Trying to figure out if I should have the car on a ramp before I start. Thanks.

For the ac belt, I needed access from the bottom. You could probably get away with doing the main belt from the top but it helped to have the bottom access for it as well.

[lucid21]

Originally Posted by autoxautox

For the ac belt, I needed access from the bottom. You could probably get away with doing the main belt from the top but it helped to have the bottom access for it as well.

Got it. Thanks.

[kevlarblue]

I just got a 2013 with 65K and it whines just like videos in this thread. Did anybody get results from the tensioner or anything else?

Mine is a 6MT and only makes the noise when in gear and under acceleration and it sounds like it comes from the transmission or driveshaft area. This is not consistent with a tensioner in my opinion because the whine is not present in neutral at any RPM.