What is that awful squeaking???

[Mkultramega]

Hey everyone!

Since I got my 94EX M/T its been making an awful squeaking under the dash just above the clutch pedal. Here is the info I was able to put together:

It sounds like a rotating shaft that needs lube. Think a blower motor thats going bad.

It happens ONLY when the truck is in any gear and ONLY at 1500RPM's or above. If I take the truck out of gear at 60Mph, its dead silent. Put it back in gear and the squeaking starts again as soon as I let the clutch out.

Depressing the clutch halfway stops the noise.

Rolling down the window, I don't hear the noice from the outside.

Before I go nuts!

 

[Anime]

The clutch master cylinder shaft sometimes can develop a squeaking noise when you push the clutch in or let it out, and the bracket the clutch pedal is attached to (along with the brake pedal) can also allow squeaking if it cracks or breaks from age and/or having to mash the pedal into the floor due to a bad clutch slave cylinder or air in the system, but there really isn't much else in the area above the clutch pedal that would cause a squeak but stop when the clutch is pressed.

It may also be what you're hearing is a whistling noise from the IAC valve on the engine intake, it can develop a really annoying noise and either needs to be cleaned or replaced to stop it.

If you can get it to make the noise by putting it in gear and bumping up the RPMs to 1500 while parked with the clutch depressed, you can try and pinpoint the source using a piece of hose or tubing, holding on end to your ear and moving the other end around under the dash and finding where it's the loudest.

If it only makes the noise with the clutch engaged and/or the vehicle in motion, it may be something related to the clutch master cylinder or hydraulic system, or could even be power/drivetrain related and the noise only sounds like it's coming from under the dash but is really in the front end, or could even be coming from under the middle of the vehicle but is just resonating in such as way to sound like it's coming from the firewall.