[Krisp97]

Taking my car back in tomorrow to see if it can be replicated. Switched to stock intakes and the noise still occurs when colder out. Sometimes I have difficulty replicating the sound, but holding out hope that they can diagnose it. Something does not sound right that's for sure.

Thinking it actually sounds a lot like the secondary air pump whistle I have heard on E46's. Will see if they can replicate the sound. Told them keep it as long as they need as I have a spare car. Hoping they figure this out!

[GoldfishTX]

Originally Posted by adameaton

The diff binding is any time I am pulling out of a parking spot with the wheel at or near full lock. The front end of the car shifts and it is pretty noticeable. I havent decided if this is worth a trip to the dealer or if it is normal. My jeep with a front locking dif would do the same thing if it was in 4WD on pavement - which was to be avoided.

Did you ever take the car in for this?

[Krisp97]

Car is at BMW the last few days, they have finally briefly replicated the sound, still trying to pinpoint it. Unfortunately the weather has warmed up and that makes less likely to happen.

Service advisor said that they will continue trying until they figure it out. I smell a TSB in the works since others are having similar issues! I have yet to see someone report back as to what exactly is causing the squealing/whistling sound on cold start, so I am on a mission.

[Krisp97]

They have been cold starting it once a morning trying to replicate the sound, they have narrowed it down today. The tech thinks it is a pulley sound, the sound went away before he was able to identify which one.

They are going to try again this afternoon. I thought all along this was a pulley sound! Kind of frustrating but still grateful they have been persistent in trying to figure this out. Will report back once I have an answer in hopes of helping others with the same issue

EDIT: They have decided to replace the belt to see if it fixes the issue before going further such as pulley replacement.

[Krisp97]

The belt was replaced. They tested it again with the recent drop in temperature, the noise has persisted.

I was contacted by the service manager and told they are opening a case with BMW NA and plan on getting audio clips of the sound to submit over.

I am two weeks in without having my car, luckily have a second car to drive in the meantime. I am eager to hear what they determine this to be. It is frustrating, but they have been nothing short of helpful and determined.

[Roarkandrew]

Did you get this issue resolved I am having the same issues with cold start and today in traffic I had an awful belt squeal as if a tensioner is going bad

[Krisp97]

Originally Posted by Roarkandrew

Did you get this issue resolved I am having the same issues with cold start and today in traffic I had an awful belt squeal as if a tensioner is going bad

I have not, it is intermittent, only when first started in the cold weather such as in the low 30's Fahrenheit and below. Not once at operating temp or warmer climate.

[Roarkandrew]

Mines the same way

[Berzerker]

I actually notice this sometimes as well. It seems to go away after a few seconds though. I don't think it's an issue.

[NicolasB]

Cold start today, mine did it 20 seconds then stopped. Oh well I guess.

[ObsessedM3C]

did we ever get to the bottom of this? temps dropped to -20C and heard the same squealing noise and jumped straight to the forums. I’ll see if I can record a sound clip later tonight