alprzy

I've had a recent high pitched whistle coming from somewhere on my 92 LT1. As most annoying things it is intermittent but happens most often during warm up (say the first 15-20 minutes of driving) but can resurface later on for a few seconds. The typical whistle noise lasts about 3-5 seconds then stops, or I can make it stop with the clutch pedal down.
My recent work done on the car (this driving season) has been Opti Spark replacement, water pump, ignition wires, brake calipers, pads and slotted rotors, axle hub bearing and u-joint (passenger side only). The whistle actually started shortly after brakes, axle bearing and u-joint were done. I want to get this squared away before winter storage coming up in 2-3 weeks. Any ideas or places to start looking would be appreciated.

fake

You have a vacumn leak problem could be the China wall on rear of intake! Is this a high milage car?

alprzy

Just hit 70,000 miles.
And just for clarification, did you mean fire wall? Not China Wall?
I've been to the Great Wall twice and don't need to go back again, ha ha...

ZWILDZR1

He means the back of the block where it meets the back edge of the intake. What kind of air filter and housing are you running? If it's a stock LT1 air cleaner that has been opened up put a towel over the air cleaner box to see if any change in the sound.

bolowbc

I had a loud intermittent high pitched whistling noise, which sounded like a squeaking noise. I was wondering if it was belt/water pump related since it seemed to squeak faster at higher RPMs... most audible when the car was stopped at idle and went away at speed. Turns out it was the intake gasket. Seemed to mostly happen after warmed up.

bjm206

I had a similar sounding problem on my 92. Turned out to be the power steering pump. Easy to test...just remove the serpentine belt and run the engine. Since the water pump is cam driven there is no danger of overheating just keep an eye on the system voltage.

bjankuski

The fact that the whustle goes away when you push the clutch makes me think two things. Are you positive you are not stepping on the brake at the same time you hit the clutch. This could be the vacuum canister on the brakes. The other thought would be a bad throwout bearing on the transmission that is whining and stops when you put pressure on it.

alprzy

Thanks for the info, I never hear it at an idle, only while driving. Would that eliminate that possibility?

alprzy

Thanks for your reply, definitely not stepping on the brake and clutch at same time. But since while driving and the whistle comes on and can be stopped by pressing down the clutch makes perfect sense it's related to the trans in some way. Will need to wait till spring for me to have throwout bearing checked but will do it for sure.

johnlee33

I had what sounds like similar issue on my 96 w/ comparable miles, turned outer to be idler/tensioner pulleys

Calderone

Can you record it or strap some action camera inside the engine to check exactly how's the whistle

Customer136

I have the same problem in a '94 LT1, 92,000 miles, same symptoms and similar thoughts, but I don't see what the resolution was here.

Car makes whistling noise which usually stops when fully warmed up. Pitch does not change noticeably with engine RPM or speed, so I reasoned it's air whistling by something; as does not seem to hurt performance I decided that it's a feature and not a problem. I also noticed recently that it goes away when I push in the clutch or leave the transmission in neutral and coast and failing bearings ran through my mind, but then realized that when I push in the clutch or leave the car in neutral the motor is idling under no load -- so this is inconclusive after all in to distinguish between rotating parts and airflow? Any further thoughts?