What is this whining noise I am hearing?

[braq]

Hello,

On my 1991 Sonoma when I drive between 5-20mph I get a high pitch whining noise. It is loud because it turns heads in parking lots. Well I got the truck up to 40mph on a straight road late at night, and turned the truck off and put the tranny in neutral. It still made the same noise. What can this be, I took it to a few mechanics, but they can't find anything wrong with it, because when the truck warms up it usually quiets down.

[PSL_240z]

Okay, this is supposed to be a Z forum. So I'm guessing this may get moved.

 

To attempt to answer your question though: If your road was flat, and the suspension wasn't really working, the only thing moving are the wheels, drive shaft, brake discs/drums, and some tranny internals. My guess is that it's the wheel bearings or brakes. If you have rear drums, then check to make sure the parking brake self adjuster hasn't malfunctioned and caused excessive rubbing. If that fails, replace the wheel bearings.

 

By the way, never over pack a wheel bearing. I have seen some people do 100% pack and it makes me cringe. This does not help the bearing, it just causes overheating due to all the churning of the grease. Bearings should be packed to 30-40% and then worked in.

[ezzzzzzz]

It's the neighbor's cat.

[Cannonball89]

I used to have a 1996 S-10, and mine made a whine at low speeds too. I found out the front brake pads weren't installed right by the idiots at Midas and were sitting in the caliper at an angle. That had made them wear down to metal on one end in less than 5,000 miles. So check your pads to see if they are down to metal anywhere.