Thread: Whirring Noise - AC related

Yes, that is on my list of annoying things I need to deal with. Mine only occurs with A/C on and I have been told that it is the compressor bearings. Jury is still out on the diagnosis (although I am inclined to think it is correct), the pulley bearing is also a common fault and a cheaper fix - but I think that would make noise all the time. Understand that it will cost about $1K to replace and regas ... so it is still on the list of things I am ignoring until the annoyance outweighs the expense !

Cheers,
Mick

My vehicle has been experiencing this AC on/off noise for 12 mths.

I've been to an indy who went right through anything associated with the AC and anything else associated with the accessory drive belt. Nothing found.

Seems to be associated with AC load at low engine revs only.

I suspected AC bearings but two mechanics so no. Pulley bearing discounted

Do you use the auto AC ?

When you find a source/fix I be interested.

Also had a LR dealer assess it but still nothing found???

Just for clarity on my particular noise - it is most noticeable as a whirring bearing kind of noise when slowing down with the AC on. It is not audible ever with the AC off. I am able to reproduce the noise, at times, by having someone gently rev the engine with the AC on high and it is audible as the revs decline. Best done when at normal operating temperature as this is when my engine is at is quietest (petrol engine).

The fact I can reproduce the noise, sometimes, leads me to think it is AC compressor - if you can't reproduce the noise it will be a challenge to diagnose. HTH a little & good luck !

Same on my V8, it's the noisiest part of the engine. I think it's the compressor bearings myself, as it only occurs when the AC is on....

I had the same whirring noise, like a noisy bearing. You could hear it most of the time but worse at low revs and especially at idle. It was only evident when a/c compressor was engaged. With the a/c turned off it was silent.

I took it to the local auto electrician guy who also services car air-conditioning. He diagnosed low compressor oil? Had it serviced for gas and oil about 3 months ago and the problem went away.

Had that in the D3. The AC compressor was replaced under warranty.

Interesting Drizzle, my air con seems cold enough but I know that the refrigerant also contains the lube. I might see if a gas/oil top up stops it.

Ditto to that idea !