I have an '05 short wheelbase Trailblazer LT with the 4.2L motor. It has an auto tranny w/4WD and about 27,000 miles on it.
It makes a whining or grinding noise that increases and decreases with engine speed and even does it at idle. Does nto matter what gear the tranny is in, it still makes the noise. It sounds exactly like the noise made when you turn the wheel on a car that needs power steering fluid. Only about twice as loud. (And yes, before you ask.I did check the power steering fluid level, the box and the lines. All look ok, no leaks and fluid level is where it should be.)
I have been told various things - fan clutch, belt tensioner, etc. I checked the serpentine belt and it looks good - no cracks.
If I open the hood, the noise generally seems to be coming from the driver's side of the engine compartment but I cannot pin it down.
UPDATE: I replaced the serpentine belt, belt tensioner and the idler pulley and the noise is now gone. Belt looked ok, but since I had it off, I thought I would change it out.
Funny thing is I don't remember the truck ever running this quiet. Wonder if it was a problem since new and just got mroe noticeable over time.
August, 9, 2007 AT 2:41 PM
I couldn't beliieve it when I saw someone with the same make/model SUV and the same problem (whining/whistle) sound that I've had the last month. It was so strange when it happened, because I knew it never made this noise before. I have only 35K miles and have had no problems until now. I may try your solution and see what happens. Thanks.