Car is a 1998 Lexus gs300. In the last few months of driving the car (car has not been driven for 2 months), the car was making a loud "humming" type sound from the engine area.

It is rather a loud sound, which can be heard from outside the car, and inside. To most non car people, they may pass it off as the actual engine.

So I just finished changing the plugs and doing a brake job on the car. I decided to remove the drive belt and see if the sound would go away (as per a mechanic buddy).

The sound went away when the drive belt is removed.

MY friend said it could be a bearing in one of the components, but don't know what to look at, any idea's

 

If you remove the belt and it stops humming then one of your pulley is bad.

 

would this be the actual pulley itself or the entire unit (example power steering)

and is there anyway to determine which pulley, dont really have anyone that has extra's pulley for me to test them all out.

 

after you remove the belt spin each pulley by hand. Especially your compressor. I bet its your compressor clutch bearing also spin the idler (tensioner) pulley

 

sorry for the delay, been busy.....

So i spun the pulleys...

Alt pulley - stiff but spins
Power steering pulley - spins but not freely, maybe half rotation, small bit of play back and forth
AC Pulley - spins freeely, one spin will do a few rotations
Water pulley - spins, same as alt maybe
Idler pulley - spins freely, but not as good as the one in my other toyota

The sound seems to come from the driver side, so AC or power steering. Happens when A/C is off or on

 

If it is the ac clutch bearing it will do it on or off Wichita one made noise when you spun them?

 

stop by harbor freight & get a stethoscope. that will give you the best idea on which one is going bad. i think i got mine for 4-5 bucks. then you won't really have to remove the belt to check which one is noisy. plus it will give you a better idea on which one is noisy.

 

this is gonna sond stupid, but do i spin the pulley's with the car started...........