944Play

Suddenly, the 944 has been making a weird screeching/whistling noise, but only at 3500 and higher RPMs and wide throttle openings. Warm or cold, doesn't matter. It sounds like it's coming from the rear half of the car.
Fuel pump was my first thought.
Then I thought it might be an exhaust leak, so I undid and reassembled the muffler flange. No change in the noise.
I would have expected a noisy fuel pump to make a much WHINIER, mechanical sound. This is really high-pitched, like a dry bushing or something.

Edit - Oh yeah, also it gets louder with more gas pedal/RPMs.

Dales944

Hello! My fuel pump makes the notorious whine sound. It is regardless of RPM and more noticable on warmer days. The sound is really high-pitched, but it constantly swells like an airplane passing over your head. So, based on what you've said, I'd say it's not your fuel pump. By the way, is the sound definitely coming from the passenger side rear? If so, maybe it is your fuel pump. The pump is mounted under the right rear of the car.

Good luck!

944Play

Okay... the noise is totally absent at idle, but chirps up when I stab the throttle to match revs and whatnot. Maybe my CO test tube (stub) is leaking. When the bracket broke off the cam tower, I cut it down to a couple inches and crimped it off.

It really does sound like it's coming from the back, but what else could it be? Gonna go check this out... BRB!

Update: Well, it IS the exhaust, and it IS coming from the back. It's the exhaust tip! <img src="graemlins/c.gif" border="0" alt="[ouch]" /> The PO welded an ANSA tip (which actually looks quite nice IMHO) to the stock muff, and it's whistling like an old Beetle.

Strange that it happened so suddenly.