2001 K1500 Yukon Vortec 5.3 4WD

[squeaker]

Soon after purchase a chirping noise started from the front area of the engine, then progressed to sort of squealing. These noises came and went, but now it's all the time, especially in cold weather. (How do you sell a vehicle that is doing this!) The dealer has replaced the idler pulley, alternator, and fan belt. They said others have the same problem, but they don't know what causes it. It's pretty embarrassing at a stoplight and is getting worse. Would appreciate any ideas. Thanks alot!

[herefordman]

I have a 97 that does this to from time to time, I'm not sure but I think its the back side of the belt slipping over the water pump pulley, as this side has no grip, and that fan is plenty big !!
And my truck has 300,000k on it and the back side of that pulley actually looks a little worn.
One way to find out is when the belt is squealing spray a little oil on it, if it goes quiet, even for a couple of seconds, then its definitely the belt slipping. Watch the pinkies !!!!!!

[99ssconv]

The power steering pump pulley may be positioned too far inboard on the power steering pump.

Correction
Follow all of the current diagnostics in the Service Manual.

If the concern is not resolved, then reposition the power steering pump pulley on the power steering pump shaft. Following the applicable Service Manual procedure and using J 25034-C, reposition the pulley outward from the end of the shaft by 1.0 mm (0.040 in.). This will leave the shaft recessed in the pulley.

[squeaker]

herefordman and 99ssconv, Thanks very much to both of you for your input. Really appreciate it. Will pass it on to the service guys next week.

[squeaker]

herefordman and 99ssconv, want to be sure this gets posted in the right place; I'm new here. Thanks very much for your input. Am taking the Yuke for service next week and will go over it with the service guys. A complaining woman needs backup sometimes. Big thanks.

[squeaker]

Originally Posted by 99ssconv

The power steering pump pulley may be positioned too far inboard on the power steering pump.

Correction
Follow all of the current diagnostics in the Service Manual.

If the concern is not resolved, then reposition the power steering pump pulley on the power steering pump shaft. Following the applicable Service Manual procedure and using J 25034-C, reposition the pulley outward from the end of the shaft by 1.0 mm (0.040 in.). This will leave the shaft recessed in the pulley.

SSCONV, your suggestion totally solved the problem. I showed it to the guys at the dealership, they followed your advice, and we have had no noise ever since. You're a genius. Thanks a million.