2015 Hemi A/C Issues

[Hopium1]

Reaching out in a hail mary. couple shops have been unable to help, throwing money at the obvious hasn’t helped yet either.

2015 Hemi 5.7, 130k miles.

What: Distinct high pitch whine/bad bearing grind when AC compressor engages. Can be heard from inside the cabin. Popping the hood and can not locate the sound. Correlates to engine rpm. Very obvious sub 2k rpm, such as when decelerating to idle.

Replaced:
-Ac compressor, noise is now (immediately upon replacement) worse then the original ac compressor. So that was a fun waste of money.
- blower motor
- idler pulley, tensioner pulley.
- water pump blew up on the highway and got replaced prior to/as this noise began to develop, 10k miles ago.

The noise is driving me up the wall. It is not just the compressor running, do not hear a similar grind/whine in any other vehicle I have owned nor been in. I drive very remote areas which does not lend well to hearing an obviously failing part sound.

Any help would be welcomed.

Thanks for looking/reading.

 

[Atcer2018]

So the noise is only present when the AC compressor engages?

 

[Hopium1]

Correct. Hence the initial replacement of the compressor.

 

[seems fishy]

If you can hear that the sound is coming from the compressor ,then I have to ask,when it was replaced(1),was it a new compressor or used?(2)Who did the new install of the compressor?If you paid somebody to replace it,with a new,or rebuilt unit ,go back and let them fix it.If it was a used unit,it does not surprise me if it makes a noise.Whether or not, maybe you replaced and recharged the system then , this would be helpful to know before answering.Did someone flush your A/C lines with Nitrogen before the compressor was changed over.When an old compressor is the culprit it potentially will contaminate your old refrigerant with debris.Make sure your lines are flushed before that debris can damage a new compressor,install.Also when installing a new compressor,if you over charge it you can damage it.There are specs on how much oil to add,.This explains why I asked ,who changed the compressor.

 

[Daw14]

Did the new comp come with a new clutch ?

 

[Jeepwalker]

Does the AC operate properly? Blows 'cold' air?

I didn't specifically read this in your description: if you have a helper inside the cabin raise and hold the RPM, then drop it in the way you would normally hear the noise...you're saying you don't hear anything unusual at the engine compartment?

Does the noise change (or occur more) when the vehicle is cold/hot, or outside temps are cold, or warm?

I would look into the alternator. Or the idler pulleys too. Using the alternator puts extra strain on all of them. I was hearing a strange noise in a car a couple of weeks ago. I removed the drive belt and rotated all the assemblies and the alternator was SO tight ya couldn't hardly rotate it by hand. And on another vehicle also recently, the alternator bearing was running dry and I could feel a flat spot and 'hear' the bearings fall as I rotated them. That's the kind of situation which might cause a grinding noise. Or maybe the shaft where the brushes ride is grinding itself.

Basic troubleshooting would be to remove the drive belt and feel the assemblies by hand. An experienced tech should be able to 'feel' if anything odd is going on.

IDK what the EXACT issues were with the previous AC compressor, but did they inspect/clean the expansion valve? An internally failing compressor can put sludge /shavings downstream, which could build up/get caught there. And possibly make funny noise. That's why I asked if the AC was working properly.