[loljohn078]

Hello! My name is John, I'm new here.

First of all, the car;
Saab 9-5
2.0t B205E
2001
225hp map

I am experiencing an issue where there is a very loud high-pitched whining/chirping/screeching noise when boosting above 0.5 bar of boost pressure.

It only occurs when driving, so, under load.

The sound was already present when I got the car. I have replaced the following parts;

Recirculating valve + hose
Boost Pressure Control Valve + hoses
All vacuum hoses
DI Cassette

I have also checked the intercooler hoses and intake pipe.

Does anyone have an idea? Thanks in advance.

 

[Nocturne]

When my car was doing that it was the exhaust manifold bolts getting loose. Tightened up all the bolts including the turbo manifold bolts and the noise was gone.

 

[loljohn078]

When my car was doing that it was the exhaust manifold bolts getting loose. Tightened up all the bolts including the turbo manifold bolts and the noise was gone.

Thanks for your reply. After checking the manifold it seems that the far most left and right studs have snapped off. Could this be the reason for the noise?

 

[Nocturne]

Very well could be. Basically what you're hearing is escaping pressure (think of a whistling tea kettle when the water boils). More boost = More pressure. It'll find it's way through the first available outlet no matter how tiny it seems. It takes less than a mm to allow that type of high pressure to start escaping.

 

[unclemiltie]

as mentioned, exhaust manifold looseness

or the gasket between the manifold and the turbo
or there is a hole in the flex pipe on teh exhaust

I've had all three on at least one of my cars, all with that whistling/whining when there is a lot of exhaust.

 

[loljohn078]

Thank you for your replies. I will fix the broken off studs this saturday. I'll update after!

 

[wks1510]

This was happening on my car as well. I chased it for about a year until I decided to tear everything apart.
It turned out that my new manifold gasket had blown out and was shooting thin pieces of metal into the turbo. If it sounds like a playing card on a bicycle wheel, this could be your problem.

I opened the turbos up took the pieces out, inspected for damage (there was none as its very thin metal) and put everything back together with new gaskets.

I also had to install Heli-coils into the block as some of the stud holes had stripped out.

Its been about 6 months and I haven't had an issue yet!

 

[bob3000]

You also ought to address the underlying cause of the broken studs which is more often not a failure of some of the engine mounts.
.