So all of the easy stuff has been done. Replace Belt, Replace Tensioner, Replace A/C compressor, Replace Idler Wheel, Replace Alternator, So the only 2 pulleys not replaced are that for the fan, ( its not squeeking there ), and that for the Harmonic Balancer pulley and balancer.

Ok now here is a twist, since the truck has 165,000 miles on it, it has developed small leaks around the oil pan and around the cam covers. So since I do see slight wetness of oil on the balancer wheel behind the pulley for the belt, could the problem with squeaking be that ??? I am trying to test all things before actually replacing the harmonic balancer and the pulley in front of it that holds the serpentine belt.

I also feel I need a good boom microphone so I can isolate where the noise is coming from. Any and all ideas welcome, since the weather is breaking to the nice side and would like to get started on it.

2002 Chevy Express 3500 5.7 EFI

 

Water pump?

 

mechanic stethoscopes are helpful
sirometers are an innovative why to check for bad pulleys.


you replaced only the serp belt not the a/c belt? was the noise still present right after belt replacement?


if you spray the belt with brake cleaner, does the noise go away briefly?

 

Will check that, I suppose I can remove the belt and try spinning this system to see if it is making noise, currently no overheating problems. Thanks again.

 

Only one belt no A/C belt, I have a regular stethoscope hard to get in there, might have to start disassembling the front area, radiator, A/C stuff etc. Noise does vary with addition of Belt Dressing on the belt, belts have been replaced enough to know its something else. I will get this problem but the whole darn front end might be on the ground to get to it, haha ouch.

 

have you tried taking the belt off and running the engine? would give a solid answer if its belt/pulley related or engine.

 

....running the engine for 30 seconds max.....without internal waterflow....

 

Yeppers, have done that and it doesn't squeak with the belt off. I am starting to lean towards it might be water pump.

 

One thing I saw that I didn't like was I tried running the car with the radiator cap off, and normally I would see a flow of coolant with a healthy water pump, but instead it was stagnant and just flowing over slightly. Might be an indicator of the water pump being the issue. Dunno really.

 

So the 3 mystery pulleys now are the Power Steering Pulley ( don't think the sound is there ), the Camshaft / Balancer pulley, and the Fan Clutch / Water Pump pulley. No way for me to tell just listening to it so might be a process of elimination.

Now the next issue is Duralast which is a little cheaper worse than the AC/Delco, Since Chevy uses AC/Delco might try that tensioner and belt combination a ( 100 dollar test 8-( )