So my 2003 350z started making this whirring noise when the AC is on. It actually started making this noise last summer but it wasn't as loud. Haven't had a chance to diagnose it yet but the AC still blows ice cold. No mods on the engine except an AEM intake and a Z1 oil cooler. I plan on removing the belts on my days off and check each pulley and compressor but I was wondering if any of you know from the top of your head what it could be. My first guess is the AC compressor? Video on the link: Thanks in advance.

 

Hey Kuya,

The whirring noise is there, but it's hard to pickup in the video (would be better if you got the microphone near the engine bay). My money is on the compressor bearings since the noise immediately disappears when you shut off the AC. So I don't think you have a idler pulley bearing or belt issue. Most likely the compressor clutch is slipping/shot or the compressor itself is done for, either way the entire compressor should be replaced if confirmed bad.

Quick Heads up, if you determine the compressor is at fault, then typically to maintain parts Warranty, you need to replace the condenser, receiver/dryer, and expansion valve. Unless you have an AC recharge machine, this is best handled by a professional. Typical procedure is to evacuate the system (suck out all the old freon for proper containment and disposal), replace parts, pull a vacuum on the new system to check for leaks, then re-fill to mfg. specs.

This is a must in the case of compressor bearing failure. You don't want metal fragments contaminating and destroying your brand new compressor!

If you plan to do the work yourself, you run the risk of the compressor failing and you won't be able to cash in on the parts warranty. This is one area of vehicle maintenance I still take to a pro for. I don't have a license for purchasing freon and I don't have the tools required for evacuating and recharging the system. NOTE: Don't even bother with those little recharge cans from the local parts store, those are garbage.

Cheers!
-Icer

 

That's what I'm thinking too, bearings in the compressor. But yes, I've taken my other cars in the past to evac and recharge the AC unit when doing something major with the AC units. Back in the 90s when $$ was in an issue, we use to just release freon in a heavy towel lol. Thanks for your input.

 

I have the same identical whirring issue as well. My mechanic is ordering a used ac compressor to replace mine and will see how it goes.

the whirring is very prevalent when during the day when its hot!