Loud Grinding/Rattling Noise from Engine
 

2008 CRV 114,000 mi

2008 Honda CRV 115,000 mi

A friend just brought over his 2008 CR-V (mine is a 1998 model) because I have a shop and do work for folks I know.

It's making a reasonably loud noise from the general area of the accessory drive belt (rattle/grinding noise). I am also hearing a mechanical gear/bearing/bushing noise that sounds like it is coming from the center of the engine, though if the oil cap is removed, none of this noise is audible from the valve cover.

I put a stethoscope on the P/S pump, alternator, and whatever else I could reach from above, and could not ID the source of the noise. As is often my habit, I Googled, and came up with this YouTube that sounds almost EXACTLY like what I am hearing, but alas, this poster had not yet ID'd the noise either.

Anyone recognize this Click to Watch/Listen:

Loud/Grinding/Rattle Noise

and have a fix for it? I was thinking the usual suspects (idler/tensioner/water pump, maybe an accessory like alt, W/P, P/S Pump bearings, etc), but thought I'd ask here before tearing things apart.

I searched the Forum and read 9 pages of "Noise Complaints," but none matched exactly

Thanks-
Bob

with the milage it has, has the serpentine belt been changed or the tensioner may be the noise. it may be a pain, but if you can disconnect the serpentine belt and see if the noise still is heard,

Found it!
 

I first thought of the accessory drive belt and idler/tensioner, but when I got the CRV up in the air and I put the stethoscope on the A/C compressor, I knew I had it. I should have been smart enough to try that FIRST (it's not the first time I've had clutches and bearings fail). DOH!!

I got in and turned the A/C on and as soon as the compressor spun up, the noise went away. Evidently the A/C compressor clutch/bearing are shot because I can make the noise come and go by just cycling the A/C off and on.

I just need to see if my friend wants to replace the whole compressor, or if we can replace just the clutch and pulley (bearing) so we don't have to disturb the Freon charge and buy a new receiver-drier and recharge the system.

Thanks,
Bob