Inlaw purchase woes

Geez… Needed a four wheel drive down here on the coast of NC to do some fishing. Bought my gfriends father’s 99 tahoe which has 175,000 miles on it for a couple grand on a pretty fair payment plan. Since its arrival in the south ( the tahoe is from NJ) there has been a constant noise from the belt system. I have gone ahead with the diagnostic suggestions from the local big time shops here in Wilmington NC and replaced the ac compressor, belt tensioner, alt, and water pump. OUCH! all at different times but in the last three months. This is not how financial aid is supposed to be spent. I STILL have a chirping sound when RPMS exceed 2000. I need help!

In your laundry list there should we assume the belt was also replaced?

yup… a couple times! checked the p/s pump pulley and the pulley is about 1/16 on the inside of the shaft. That was on a hunch from another forum. I am not car savy to say the least. It was at firestone today!! i picked it up, ran fine for an hour and then started to slightly chirp… and continues.

You might narrow it down if you get a mechanic’s stethoscope and listen for the source near anything that turns. You can make one with a vacuum line and a bolt…

Firestone is not really one of the places that a vehicle should be taken to for servicing. Unless their business model has changed over the years (not likely IMO) they can be somewhat shaky to put it politely.

What about an idler pulley seeing as how you have replaced the tensioner?

Does your model use an air pump (a.k.a. smog pump) not referring to the A/C compressor?
Smog pumps are notorious for squeaks, squeals, rattling and rumbling.

idler seems ok… checked that already. Appreciate the help… thinking that one of the pulleys is out of alignment… Wanted to see if anyone had any experience with that. thanks for the tip about the vacuum hose.