Hi guys,
My 2008 MINI Cooper S just started making a whistling sound---the whistle pitch varies with the throttle level. As you step on the gas, the pitch goes up. As you shift through the gears, it follows the engine rpm in terms of pitch. My car almost sort of sounds like a jet turbine (except not that loud of course). I checked all my CAI lines and they're all fine. Listened to the turbo and the sound isn't coming from there. It sounds like the whistle is coming from the left side of the engine (the timing chain side), but the sound seems like it's coming from lower down the side, not at the top of the engine. I got an "engine malfunction" warning on my navigation and a "reduced power" warning. I've had this code once or twice before (several thousand miles ago), cleared it, and haven't had any problems since. Sounds like others on NAM have had this fluke code too. I cleared the code again and there aren't any pending codes and it hasn't put a code up since. Last note: it is cold out, ~14 degrees, but after 20 minutes of driving the whistle is still there--not sure if the cold has something to do with it or not. Any idea what's causing this sound? Thanks!

 

I just bought my used 2010 S three weeks ago, a few days after driving it off the lot I started noticing a high pitch whine from the same area. It sounds similar to what you're describing, it seemed to gain pitch steadily with RPM, gear didn't matter, even in neutral.

Although, mine didn't sound like a whistle, more like bearings. I originally thought it might be the turbo bearings, until I realized it was coming from the passenger side. It turned out it was the Serpentine belt tensioner.

 

Hmm, interesting. I'll have to give that area a closer look. My problem does sound like an "air" type problem though, I just don't know what would be whistling down there. The thought occurred to me that maybe the cold side intercooler tube could be making noise down there? Not sure. Thanks for your input!

 

Possible its the tensior or the belt if its the passenger side. Then check the crank pulley.

https://www.northamericanmotoring.co...e-to-time.html

 

Thanks for the part suggestions!
I just found what the problem was. There was a problem with an aux cable that I had plugged into the aux port. Some how the speakers were making the high pitched whistle and following the rpm in terms of pitch. It sounded like it was coming from the engine because the sound followed the rpms.... Not sure how that happened but I unplugged it and it's gone!

 

I was going to say it's the throw-out bearing, it also had a high pitched whistling noise. That throw-out bearing cost me $1700!