Wining Noise - Not Power Steering Pump

airitech · July 5, 2019

Hey guys, first off I hope everybody had a nice 4th of July! After several hours of going through the trouble to replace the power steering pump, due to me thinking that the noise was coming from it, after installing the new one, the noise did not go away.

Probably have had the noise for 2 years while ive owned the truck, its a 2006 GMC Sierra 1500 5.3 (Code Z) 4x4 z71. Noise follows the RPM of the motor, and I was very sure it was the power steering pump just due to listening to the engine bay, and having the general thought that whining = power steering pump. The power steering pumps performance was not bad, and the noise never changed, I was pretty sure.

Went through all of the trouble to replace the power steering pump, turns out that was not the wining noise. I guess I only "wasted" around 50 dollars, got the pump with a 25% off coupon from advance auto, after i return the core ill get back my 75 dollars so im not too upset about the cost, the time was more frustrating.

I guess my question is, what other component that is belt driven has a history and or capability of creating a wining noise? Alternator? Water Pump? Cant be the AC compressor, when AC is off wine is still present.

Thanks in advance to any tips/suggestions!

riverbanks · July 5, 2019

Take a screwdriver,put it to your ear,the handle end,put other end on everything with a pulley,the whine will be very noticeable

airitech · July 5, 2019

4 minutes ago, riverbanks said:

Take a screwdriver,put it to your ear,the handle end,put other end on everything with a pulley,the whine will be very noticeable

Would a stethoscope do the same trick? Something about a screwdriver next to my head with moving parts is slightly terrifying.

riverbanks · July 5, 2019

I didn't say,put it on the pulley,but everything with a pulley,the alternator and water pump don't bite

rjgti · July 5, 2019

can still be a/c, pully is still turning

davester · July 5, 2019

You could try taking the belt off, to verify that the whining noise is something belt-driven. You can also spin the various idlers/pulleys to see how they feel, maybe a bearing is going bad in one of them.

mjm-1957 · July 5, 2019

Take the belts off and run it, could be the oil pump or the front pump in the transmission.

diyer2 · July 5, 2019

Get a mechanics stethoscope.

$4 at harbor freight

airitech · July 5, 2019

Well gentlemen, after purchasing the harbor freight stethoscope, it IS the AC Compressor. And man I really do not feel like attempting to replace that S.O.B. AC works fine at the moment, no issues and havnt really had any that pertain to the AC compressor. Could this be an PAG Oil related issue? Or maybe just the pully/clutch system there?

swathdiver · July 5, 2019

21 minutes ago, airitech said:

Well gentlemen, after purchasing the harbor freight stethoscope, it IS the AC Compressor. And man I really do not feel like attempting to replace that S.O.B. AC works fine at the moment, no issues and havnt really had any that pertain to the AC compressor. Could this be an PAG Oil related issue? Or maybe just the pully/clutch system there?

You don't have to change the whole compressor, just the clutch and or bearing. Four Seasons and ACDelco sell a kit. Mine started making an intermittent noise about a year ago and is constant now. Not sure if it is clutch only or the bearing as the AC is always on down here. Was going to check today but it has been raining and lightning all day.

Plug your VIN in here and go to AC Clutch and Parts Section. Mine is 15-4709

https://parts-catalog.acdelco.com/catalog/catalog_search.php