Squeal/Chirp @ 1500 + RPM ? Not belt related?

[sprp85]

Hey all,

I've been looking around online for an answer but could not quite find one... so here we go..

Last Saturday, I drove 2.5Hrs to check out a 128i (N51). It looked clean inside and out (Other then torn up passenger side undertray cover.. )

The car drove fine and felt really good in terms of "solid-ness".

However, as I was returning to the dealership, after test driving it, my wife noticed odd noise coming from the front of the vehicle.

The sound came right around 1.5K RPM and up, the noise is constant, high pitched/frequency squeal and or chirp

First thing that crossed my mind was drive belt. A mechanic came over to test out the belt by spraying liquid on it but noise persisted.

So I left the dealership after the sales person agreed to get it diagnosed and what not.

However, service personnels are still clueless about the noise, after 3 days (They are not a BMW dealer so I guess it is understanble).

Unfortunately, I have no recordings of the noise, but my first suspect is Idler/tensioner pulley.

The car has around 70k miles so I assume pulleys are due for replacement?

Some other posts mentioned Rear main seal leaking could cause those weird noises, some mentioned vanos position sensor (?) could do so, etc... but could not exactly find an answer that fitted my description..

Any tips or idea would be much appreciated!!

[RCPBMW]

I have the same issue... Can't figure it out either