Can't identify squeal source
 

2007 Z, with the auto tensioner

Symptoms:

High-pitched, constant squeal. Not "chirping"
Only occurs while moving. Doesn't matter whether I'm in gear or neutral, accelerating, decelerating, or coasting.
Does NOT occur while stationary under any circumstance (revving the engine, turning on the a/c or all electronics, turning steering wheel to test power steering pump)
Does NOT go away under braking
Pulleys and all pumps do not seem to have any play. Belts appear to be spinning pretty freely (no misalignment).


I've already replaced the belt with an OEM belt, and the auto tensioner with a Gates. I chose the Gates over OEM because I've read that the OEM auto tensioners are problematic. Of note is that the indicator is showing slightly under-tensioned even with the new auto-tensioner.

Thoughts? I'm going nuts here. Since it doesn't happen while stationary, even while revving, I'm inclined to think it may not be the belts. But it does not go away under braking, so that kind of rules out brakes. Wheel bearings should be more of a thunk or click than a squeal.

take it to a certified mechanic. sound problems are almost impossible to diagnose over the internet. your squeal might be my grinding noise.

Dude if it only happens while you're rolling then it has to be something that rolls.


Maybe a wheel bearing, bent backing plate, brake squealers hitting rotors.


If you're motivated to fix it yourself start by taking the wheels off and inspecting.


Does the noise change pitch when speeding up or slowing down?

Jack up the car at each corner. Spin the wheel. If you hear the squeal, then get under there (use a jack stand) and figure out where the sound is coming from. Sometimes, a rock will get jammed between the rotor and the rotor plate and this can cause the squealing sound you're referring to.