nfnsquared

A/C runs great except for this new noise. Cannot hear it from inside the car and can barely hear it with the hood closed.

Just noticed it today, haven't had time to pull the drive belt and check the A/C clutch pulley for play/feel.

I assume the pulley bearings are starting to go. Any other ideas before I dive in?

bauermd

iTrader: (1)

I would get this checked out as soon as possible and try to avoid using your A/C as much as you can. Wouldn't want your pulley bearings to go and screw up your compressor. That is a whole different beast.

dcmodels

Also check:

1) that the A/C clutch itself is not starting to come-apart, that is, that the multiple parts on the clutch are in good order

2) the clearance between the clutch face and the A/C compressor, as there is a TSB for RDX's for a worn clutch with too much clearance, so that it rattles, or does not properly engage, that calls for clutch replacement. There is a clearance specification for the RDX, don't know it for a TL. Don't know the TSB number for the RDX.

3) the A/C clutch relay, more info here:
https://acurazine.com/forums/showthread.php?p=14545907#post14545907

Turbonut

iTrader: (1)

There are many items that can cause the noise, e.g. overcharge, blocked condenser, cooling fans, low voltage to clutch, but I'd begin by looking to the compressor internals. If it were the clutch/bearing, the noise would be audible when the A/C is not engaged as the clutch bearing/pully is only operating, but when the compressor is engaged the clutch/bearing is turning the same rpm, so the only additional parts turning, compressor internals.
Take a hose or long screwdriver and place it on the compressor to check for noise.

Majofo

I doubt it's the bearing. I'd start at the auto-tensioner.

Majofo

I had a bearing go out on me (different car) and when the clutch engaged it would make the belt squeal something horrid like skinning a cat. When I pressed out the bearing it wasn't even that bad, but bad enough to burn up a belt. It was a bigger pain cleaning up the aftermath than it was to remove the compressor and press out / in the bearing.

Turbonut

iTrader: (1)

^Bearing and clutch can disintegrate, but normally when the belt skids around the energized clutch, the reed valves are bad and the compressor locks up.
You were lucky.

nfnsquared

Thanks for the inputs guys. Still haven't had the time to check it out yet, been driving all over ND the last few days. Should be able to get a look tomorrow.

I was basing my original thought off of this video from ETCG, although my sound is more of a rattling and quite faint at this point. If the bearings are worn/loose, the pressure from clutch engagement can apparently cause the bearing noise.


I'm also aware that there might be a clearance issue, although I would be surprised if that was it. I should know more tomorrow.

Majofo

longitudinal FWD.. haven't seen that in a while.

azguy

It can also be that you simply sprung a refrigerant leak and the oil is getting low causing it to rattle a little when engaged

the top two are failing ac clutch / bearing, refrigerant leak....

Majofo

2nd post in 2 years..

azguy

nice welcome to the board....

simply because I haven't been around doesn't mean I don't know what I'm talking about... worked on an 04 TL a couple of months ago... light rattle when AC clutch engaged....

popped open the hood and span off the valve caps...both hi and low side schrader valves were leaking oil and refrigerant, it was obvious on the caps... I knew the guy so I just had him buy them off Amazon Prime overnight for $16 total:

Four Seasons 26783

Four Seasons 26783

next day I popped them in, charged the oil and refrigerant... he bought me a burger.... done...

but in any event, just don't go running the compressor with possible bad clutch, bearings, or low oil inside.

nfnsquared

Well, the sound has not come back. A/C works fine. No leaks at the valves or anywhere else that I can see. I put over 1K miles on the car this week, 450 of that today. Still haven't taken a good look at the clutch and other pulleys. Might get around to it tomorrow, but at this point, I'm not terribly concerned.

azguy

take a measuring cup with water, whip off both caps with the car and compressor running, fill up the valve tops with water and see if bubbling is happening... definitive valve test... if it was rattling at any time something needs to be seen to... if you put little pools of water on the top of both valves and no bubbles, you are good there but I would start investigating it

it rattled for some reason: low oil, broken compressor, bad bearings, bad clutch... it didn't just magically fix itself... and if you ignore it, eventually you got a shot of the compressor grenading through the system, and needing $4k of evap, cond, compressor, and everything else... or the pulley seizing and destroying a couple of K of stuff on the outside

a new compressor kit with drier and seal kit and everything for $199 at rockauto but compressor replacement is a little difficult being underside behind the passenger wheel well

Rock Auto New Compressor with Crier and Acummulator