HELP...Extremely Loud Whistle/Screech???

My Sister has a 94 Camaro V6 that has an extremely loud (annoying) whistle or screech-like sound coming from underneath the hood...It's hard to diagnose which side of the engine the noise is coming from because it sounds the same on both driver and passenger sides, so I'm guessing it is from somewhere in the middle of the engine, but I have no clue...We had the alternator checked out and I just replaced it today thinking that the bearings were going bad, but apparently that wasn't what was making the noise...Could it be a small air leak from somewhere causing this noise? If anyone has any suggestions on what to check, your help will be greatly appreciated...Thank You

Bad belt / tention be my first check.

Speedo cable.ive heard a couple of these......but thats just me.........

power steering pump? there are a lot of things that can make noises unfortunetly....

when does it sound? when you accelerate from a stop? when youre just driving? when you turn the steering? more symptoms + causes of it plz

Check the belt, then start spinning all the belt driven accessories by hand to see if there is one that may have the bearings going out on it. It's kinda hard to diagnose sounds without actually being there...

I have pulled the belt completely off and started the car to see if it still makes a noise and it does. So I assume all the belt driven accessories are fine and are not what is causing the noise. The alternator and tension pulley assembly have both been replaced in the past couple of days (the tension pulley/assembly needed to be replaced and I figured the noise was coming from the alternator so we replaced it). It makes the noise when it's just idling and when it is at coasting speeds; when I'm accelerating it is not making the loud whistling/screeching noise. If anyone has anymore suggestion please let me know. If I can't figure it out from anyone's suggestion(s) by the middle of this week I'm just going to take it to a shop on Thursday...Thanks Everyone

next time post on the same thread as your original..

anyway, when you say you took off all belts, does that include the water pump, the alternator, AC compressor..etc?

if you took off ALL the belts its probably going to be a big problem...

if its a spinning screeching noise, its probably gonna be camshaft/crankshaft? (Someone correct me if they have a better idea..)

cam/crank sounds good. well in your case bad....i guess you could hope its transmission, where does it sound like its coming from. you can grab a wooden broomstick, put it on parts of your motor and put the other end plugging your ear (like put the end of the pole on the little nub part of your ear as if you were plugging your ear) and listen. you can hear the insides. its pretty fun. and it works, it workes real good. just start poking around. but make sure you dont hit anything spinning with the broom stick and mess something up. like a fan

Failed EGR gasket/tube or massive vacuum leak, (pcv tube knocked off), leaky throttle body gasket? Put a vacuum gauge on it and follow the directions, any of these conditions will be pointed out.

next time post on the same thread as your original..



:1: I'm off for the weekend and all heck breaks loose around here :disappoin