Squealing noise from 1500 to 2000 RPM

[zamimj222]

Hello,
I have a 5.3 V8 in my 2004 Silverado. When I am driving down the road and weather is under 40 F outside I get a noise like a belt squealing around 1500 to 2000 RPM. I knew the main serpentine belt was ready for replacement due to the age. I replaced it, the fan clutch, the idler pulley and belt tentioner as they all had over 100K miles. The power steering pump was replaced due to a leak and the alternator was replaced as it was failing. The secondary serpentine belt was replaced along with it's tentioner by a dealership along with the AC compressor for a leak. I cannot locate it with a stethescope and nothing gives any indication when I remove the belts as the exact culprit. Any help in this would be greatly appreciated.

 

[Maverick6587]

Were all of those items replaced recently (all at the same time) or just at some point in time? Also, are they all ACDelco parts?

I assume this happens even while parked? Possibly the water pump? Can you hear it more predominantly on either side of the engine?

 

[mrrsm]

Try removing the Sepentine Belt and very briefly...run the engine up to the 1,500 to 2,000 RPM to eliminate any possibility that the problem involves anything internal to the motor. My $$$ is a Split Bet on either a Bad Belt Tensioner... or Failing Water Pump Bearing(s).

 

[zamimj222]

All parts were AC Delco parts. All were changed within 100 miles of each and recently. It does make the noise regardless of transmission in park or in gear. Last part I tried was the belt for the AC compressor. Still making the noise. I revisited this yesterday and removed the AC compressor belt. The noise has so far not come back. I spun the compressor pulley and it is free. No noise by hand. The noise is definitely coming from passenger front of motor. I am wondering if the compressor bearing is faulty. It had been replaced at the dealership about 25000 miles ago before I bought the truck.

 

[mrrsm]

The Internal A/C Scroll Compressor Bearings are very unlikely to make any such noise. The more likely Candidate would be the Free-Wheeling Bearing for the Magnetic Clutch of the Heavy Cast Iron A/C Serpentine Pulley.

There should be some Threads covering how to solve that issue...even if the Magnetic Clutch is NOT alleged to be serviceable. Youtube also has more information on Tricks for Working over the Delphi or ACDelco Factory A/C Compressors by getting around the tricky problems of having a Non-Repairable Magnetic Clutch.