3100 horrible "wheee!" sound under load

[3100GP]

My second gen 3100 Grand Prix makes a horrible high pitched noise, like rushing air/gas, when the engine is under load but is fine at idle. This was diagnosed as a lower intake manifold gasket failure so I replaced it and it still does it. The gasket I took off didn't look bad, it had no obvious tears or failures and seemed fairly robust anyways. Is there any way to check that seal or any other things that might cause this? I'm stumped! :/

Thanks in advance.

[Juglenaut]

RE: 3100 horrible "wheee!" sound under load

Are you sure it is not the power steering pump, and or rack assembly.

[3100GP]

I doubt it's the power steering pump as the sound will show up at low or high RPM - it just depends on how much strain the engine is under. The sound isn't a whine either, it definately sounds like a loud engine, just very high pitched. I SeaFoamed the car today and couldn't locate any leaks except near the EGR valve. How loud could a leaking EGR valve/tube be?

[3100GP]

Well, I finally fixed the problem - a plugged cat! :/ I suppose the cat would let enough back pressure build up to leak out small exhaust leaks very quickly. So if anyone else ever has the same problem, check the converter.