Shreiking,screeching,loose belt noise from turbo

[Petey Turbo]

Before I say anything, I'd just like to to ask that no one reply with a remark stating the sound is normal turbo "whistle" or what have you...I have owned over a dozen turbocharged cars and know a good amount about turbo systems ect..I would just like to keep this topic alive because I am sick of the sound..I know one day this will be figured out, but if anyone has found the cause please let us (me) know..I am referring to the screeching sound that comes about at 3000 rpms or so (varies in diff. gears) util about 6000rpms that is probaly louder then the engine or exhaust..This is very annoying for me because I know it is not right.If I were to guess, I would say it is either a boost leak or a turbocharger tolerance issue..
I have not touched my car since I bought it, I just drive it..I bought it so I'd have dependable transportation but I do plan on modding it in the near future..This is why I have not tried to find the cause of this..I also do not have the time anymore..
This is my plan..I am going to pressure test the entire system the right way,if its airtight to 30psi I am going to the dealer for a turbocharger replacement, and I will get it.. If the turbo replacement fixes the problem then we will have out answer and I can vouch for people who are having the problem and having difficulty getting it resolved..Sound like a plan??
BTW if anyone has gone through this please speak up..Thanks for the space

[505zoom]

Mine has done it forever. Since I got the car, 24k miles ago. I am convinced that it is the turbo. I will know for sure here in about a month when I get my new turbo setup on the car.

[505zoom]

BTW, these are the details about when mine does it:

1. Only between 80-90mph
2. Only under partial boost
3. Goes away when boost hits 0
4. Very random about when it will actually do it. Hard to replicate when I want to show someone.
5. Sounds like metal on metal at very high RPM (squeeling, almost humming/whistling at the same time... very hard to describe)

Hope this helps clear up any misunderstanding about the noise for those of you who don't have it. I am sure that some of you are hearing it though.

[jersey_emt]

People have said it's the fact that our turbos are ball-bearing turbos.

[jred321]

mine does it, i'm not too worried. it's either the bearings in the turbo or the wastegate whistling as exhaust passes it when open. either way, if it breaks, warranty :)

[celdridge]

mine does it, i'm not too worried. it's either the bearings in the turbo or the wastegate whistling as exhaust passes it when open. either way, if it breaks, warranty :)


I dont even have this mystery sound ... mine is all turbo spool whistle ... nothing else. I feel sorry for you all though ... i hate unknown noises ... they drive me crazy.

[low_psi]

i've got the screech too. i don't care... except strangers alway gimme a "wtf boy, tighten your belts!" look...

[celdridge]

i've got the screech too. i don't care... except strangers alway gimme a "wtf boy, tighten your belts!" look...


So is the sound your talking about a screeching noise as the turbo spools up ... is it as loud as a loose AC belt ?

[Dr.Sound]

oil starvation??

many people here had this problem.

have u taken it to the dealership?

[DSMConvert]

yea I'm with sound on this one...if it wasnt ball bearing i would say the shaft is off balance and its rubbing against the intake casing, but with a ball bearing setup it reallly shoudnt have horizontal movement...

[MikeyG_U2]

Mine starting doing this when I first switched to Mobil 1 synthetic, around 10,000 miles. It's been doing it since (I'm at 35,000 now and do plenty of autocrossing where the engine spends a lot of time up high) and has never been a problem.

My screeching occurs under WOT, starting around 4000rpm and continuing until I let off the gas or shift. This is on top of the normal turbo whistle/rushing air that all turbo cars make. I have met with other MSP owners here in Chicago, theirs all make the exact same sound.

I took it to the dealer, took a tech for a ride, they didn't find a problem other than the noise itself.

I have had other turbos in the past also, none of them did this. However all the MSP's seem to do this, and there hasn't been an outbreak of blown turbos that I've read about.

As for the volume of the sound, it's easy to hear with the windows open. But with windows up and stereo on, you never hear it. If this doesn't sound like your noise, then get it checked.

[N1XRR]

Mine starting doing this when I first switched to Mobil 1 synthetic, around 10,000 miles. It's been doing it since (I'm at 35,000 now and do plenty of autocrossing where the engine spends a lot of time up high) and has never been a problem.

My screeching occurs under WOT, starting around 4000rpm and continuing until I let off the gas or shift. This is on top of the normal turbo whistle/rushing air that all turbo cars make. I have met with other MSP owners here in Chicago, theirs all make the exact same sound.

I took it to the dealer, took a tech for a ride, they didn't find a problem other than the noise itself.

I have had other turbos in the past also, none of them did this. However all the MSP's seem to do this, and there hasn't been an outbreak of blown turbos that I've read about.

As for the volume of the sound, it's easy to hear with the windows open. But with windows up and stereo on, you never hear it. If this doesn't sound like your noise, then get it checked.
Thats exactly what mine does, on the dot. Except I switched to Amsoil 10w-30 and it only does it when the car is very hot. I have narrowed the problem down to A) The turbo is ball bearing or B) The oil is thinning out and not providing adaquit lubrication. The only problem with the oil thinning out theory is that there is no metal in the oil. You can even see a fine silver-ish reflection, which means the turbo is should be getting enough oil.

The problem is, I've not heard any other BB turbo's before, not many people have. The one person I know of who works at a motorsports shop (A real one, not a nice-boy shop) says this is normal for BB turbo's.