Help: Car sounds like Shop-Vac Vacuum cleaner (91 240SX Fastback)

[car_nu_b]

Hello,

My car's engine (91 240SX Fastback) recently got about twice as loud as normal, but its not a low engine sound but a high pitch air rushing sound almost exactly like a Shop Vac Vacuum cleaner. It starts getting very loud around 3000 RPM.

When i get outside to hear where the sound is comming from, it sounds like underneath the car below the drivers seat. I thought it was the exhaust pipes so I took it to a muffler shop. He found a small hole towards the rear which he repaired but the car is still loud.

I'm not sure what it is or how safe it is to drive it. I will take it in tomorrow but want to know what it might be so that I dont go in with a total state of ignorance.

Thanks.

[rsmithdrift]

My 300 used to sound like that. Untill I replaced the catylitic converter with a straight pipe.

So that would explain it sounding like the exhaust also. And don't listen to midas, they're morons with checking cats.

[Neil]

siezed clutch fan?

[KFL]

I would check around the intake manifold for any leaks..Co-worked had a whining car..attributed to that (IM gasket)and a small exhaust leak.