[Frosty]

It's been so dang hot around here for so long I haven't driven with the windows down in nearly 5 months. Recently I've driven around with my windows down and have noticed a real loud high pitched bearing(?) noise that starts up at about 2K RPM and goes away at about 3K RPM under moderate load. I just replaced the snout bearings in the SC a little over a month ago where at the same time I replaced the tensioner pulley and both SC belt idler pulleys with the Metco kit. Below is a video to where you can hear it but my phone wasn't really catching it nearly as loud as it is in real life.

Car is out of warranty so on me to figure it out at this point. Car is a M6 2015 with 6K miles on it.

I really love this car but I'm getting REAL tired of chasing odd noises... Been nonstop since I bought it in March.

 

[Challey Cat]

It's been so dang hot around here for so long I haven't driven with the windows down in nearly 5 months. Recently I've driven around with my windows down and have noticed a real loud high pitched bearing(?) noise that starts up at about 2K RPM and goes away at about 3K RPM under moderate load. I just replaced the snout bearings in the SC a little over a month ago where at the same time I replaced the tensioner pulley and both SC belt idler pulleys with the Metco kit. Below is a video to where you can hear it but my phone wasn't really catching it nearly as loud as it is in real life.

Car is out of warranty so on me to figure it out at this point. Car is a M6 2015 with 6K miles on it.

I really love this car but I'm getting REAL tired of chasing odd noises... Been nonstop since I bought it in March.

I heard 2 noises in the video. The first one was the supercharger bypass valve which makes a high pitched whistling noise as it gets closer to fully closing for full boost right at around the RPM's you described. The second obviously was the supercharger itself spooling up. If the bearing noise you're describing can also be described as a temporary whistling noise as RPM rise in the 2k to 3k range, it's probably the bypass valve doing it's thing and is totally normal. I had the same concern in the early days with mine and once I learned what it was I actually embraced it and then it became part of the cars character which I loved.

 

[Frosty]

Greatly appreciated. I originally thought it was that a couple months ago when I first heard it faintly but it really caught my attention when I heard it the last couple of days. Yes, it's right between the 2K-3K RPM range and generally only moderate throttle which makes more sense now. Light throttle I'm not getting into boost so it wouldn't open and heavy throttle it probably opens up much faster so I don't hear the prolonged sound. Sounded like a dry bearing but putting my mind towards that valve I can diffidently see it being more a whistle.

 

[baabootoo]

Did someone else tell you needed these other parts? Any mods that caused problems?

 

[Frosty]

What other parts? The bypass is stock. The bearings in the SC and the drive belt pulleys one was noisy and since I was replacing one that was going bad I decided to just replace them all while in there. The only real mod I've done to the engine is the JLT intake. I got it more for the increased SC whine over any thoughts of performance gains. Come to think of it, I'm guessing that may also be why the valve sound may be more noticeable now too.