Strange Engine Noise

[Griffo04]

Hey guys,

I have a 95 Gtst 5spd and when driving there is a high pitch squeel coming from the motor.

Now at first i though it may of been the turbo, so i bought another one yesterday (had very very little shaft play in and out, none up and down)

and fitted it but...i still have the sound. The sound only comes when i am high up in the revs on full boost (about 8psi, thats what the guage says)

So first and Second gear mainly at about 4500-5000rpm and then upwards from there .... but not when i am in 5th gear foot flat at full boost

Would it be possible the BOV is leaking and making the sound? When revving the car from under the bonnet and looking at the BOV it seems to open slightly when it hits the little bit of boost

The only Mods to the car is a full 3" system, HYBRID FMIC, GFB BOV TYPE 1 i believe, GFB Atomic Boost controller, and a boost guage

any help would be appriciated

Tim

[mad082]

it could be your bov opening slightly and causing the squeal. it could also be a boost leak somewhere, or possibly an exhaust leak. it doesn't sound like a belt slipping does it?

[mosquitocoils]

What else have you done to the car recently? I'd be inclined to think it's a vacuum leak somewhere at one of your intercooler piping joins or something similar.

I had a shitty high pitched whining noise coming from where my bov meets the crossover pipe, turns out the gasket wasn't sealing it properly so when there was 7+psi of boosted air going past it, it would leak out and make a sound like air escaping from a tiny hole in a balloon.

[Griffo04]

Awesome thanks for your help guys...turns out it is manifold to block gasket