Car has slowly developed an intermittent low whirring noise for a month or so, which I thought might be the AC clutch.

Although the AC is working fine in cooling terms I had the AC re-gassed yesterday, in case that would solve the problem. It was half full.
BUT now the noise is much louder (louder than the engine when cruising at 50mph).
The noise is constant when the AC in ON.
It sounds like a fan with a worn bearing.
It is directly related to engine rpm.
Noise is not affected by altering heater fan control.
Tuning OFF the AC causes the noise to stop instantly.
Turning ON the AC and the noise comes on slowly after a few seconds and builds to its full volume over another few seconds.
With the bonnet open the noise is much quieter in the cabin than when driving.
Its hard to work out where the noise is coming from just by listening.
Using a sounding rod I can hear the AC clutch engaging when AC turned ON.

I see the AC compressor clutch is listed as a separate part
https://parts.jaguarlandroverclassic.com/p...and-rover/
LR017930

But I can find nothing in the JLR workshop manual about replacing the clutch.
How easy is it to do ?
Are special tools required ?
Can it be replaced with the AC compressor in situ.

Should I consider other sources for this noise ? Jules

Last edited by jules on 17th Aug 2024 5:43 pm. Edited 3 times in total

Or is the AC clutch fine and the noise coming from the AC compressor ? Jules

Jules
I have read several posts on the forum where the AirCon noise is stopped by a ReGas of system.

https://www.freel2.com/forum/topic38427.html?highlight=aircon

I can see that you have done this, but I cannot spot anyone has done anything apart from changing the whole Compressor. FL2 XS SD4 Auto 2010 2012-2017 (21k - 91k miles) (MY2011)
FL2 Metropolis SD4 Auto 2014 2017- (16k - 77k+ miles) (MY2015)
Metro in its 11th Year of (Extended) LR Warranty / Full LR Service History
(Expensive, but Trouble/Worry free - hopefully?)

Last edited by IanMetro on 30th Jul 2024 12:03 pm. Edited 1 time in total

I did that yesterday (see post) and it made it much worse. Jules

Whilst I could maybe replace the clutch , I cant do the Compressor an account of the AC gas. Jules

Sorry Jules I part posted my note whilst I was still searching.
(I have in the past, lost my note before I had finished so I tend to keep updating as I find things)

This post says clutch is running all the time and only the actual compressor starts and stops when AC selected.

https://www.freel2.com/forum/topic26608.html?highlight=clutch

This Thread from LandyZone suggests that ReGas can go wrong and start/retain the noise if fluid level not correct (I think thats what the conclusion is)

https://www.landyzone.co.uk/land-rover/fre...sy.361295/ FL2 XS SD4 Auto 2010 2012-2017 (21k - 91k miles) (MY2011)
FL2 Metropolis SD4 Auto 2014 2017- (16k - 77k+ miles) (MY2015)
Metro in its 11th Year of (Extended) LR Warranty / Full LR Service History
(Expensive, but Trouble/Worry free - hopefully?)

Thanks Ian
From what I can deduce from your linked threads it is either the aux belt pulleys (idler or tensioner) or the compressor rather than the compressor clutch.
It could also be the alternator.

So I am going to change the aux belt pulleys as they are cheap compared to an alternator or compressor and I didnt replace them when I did the cambelt 3 years ago (gosh, how time flies). Jules

Hi Jules. I think our car has a very similar problem to yours. We have recently replaced the idler pulley and tensioner so I know with our car it isn't that. You can hear the sound that our idler/tensioner was making in this video:



We've also had the air con radiator thingy that sits in front on the engine radiator replaced as it leaked all the gas out on our car:



So we are pretty sure our compressor needs changing next. I will keep an eye on this thread incase your whole compressor doesn't get changed.  https://www.youtube.com/@scottandalana4x4

Jules surprised the people who did the regas for you didn't notice the noise

^^^
Was just thinking the same.
Take it back to them and seek their advice? Landrover - turning owners into mechanics since 1948

2014 Orkney grey Freelander SD4 GS.
2004 Zambezi silver Discovery 2 Td5 (Gone)
1963 Surf blue Morris Mini Minor Super de Luxe (my little toy)

I Like Chips wrote:

Jules surprised the people who did the regas for you didn't notice the noise

Oh well, I replaced the Tensioner and idle pulleys today . No improvement.

Whilst I had the FEAD belt off I spun the alternator pulley - seemed smooth, with a one way action.

The AC compressor pulley spins smooth but I could feel some small amount of harshness when I turned the outer part (which spins when the compressor is engaged and is stationary when its not engaged).

So I'll ring garage. Jules

Took it the my local garage this am.
He couldn't hear the noise with the bonnet open, but agreed it was definitely there when inside the cabin.

He was not sure what it was and advised me to carry on searching at home as all he could do was to swap parts in and out which is what I was about to do anyway.

Interestingly, I noticed the sound disappears if you speed up the engine and comes on louder as it slows down. Does that help to point to a source ??

Ive attached two youtube videos:

https://youtube.com/shorts/cwrZ_EDyvQI?feature=share

https://youtube.com/shorts/byD1OD97t0I?feature=share

the video doesnt really capture the sound properly; its a much more irritating/ grating sound - hard to put up with on a long journey

Any suggestions?

Ive changed the threads title as its moved in a different direction to that I originally thought it would. Jules

Interesting, I don't really hear the noise while the vehicle is stationary (yet??) it only really become intrusive as I'm driving but similarly it seems to get less intense with increasing revs and louder when coming off the accelerator/slowing down. I did try having the AC on as I drove home end of the day recently and the sound was still there when I parked up but it didn't really help trying to nail it down and faded standing at idle.

Did you get any information on whether they put oil in the system when they did the re-gas?

The clip of you revving the engine sounds like Alternator Belt being stressed on the overrun, although I would also expect it to be there with AC off.
Is the noise in proportion to the pressure inside the AC unit perhaps?


PS - One lucky thing to note is that as you get older you hear less and less problems (and other things).

- My FL2 is becoming limousine quiet, and when asked why I haven't heard my wife calling, I explain that it is 'Male Pattern Deafness'. That is, my hearing is becoming increasingly selective in what it wants to hear. FL2 XS SD4 Auto 2010 2012-2017 (21k - 91k miles) (MY2011)
FL2 Metropolis SD4 Auto 2014 2017- (16k - 77k+ miles) (MY2015)
Metro in its 11th Year of (Extended) LR Warranty / Full LR Service History
(Expensive, but Trouble/Worry free - hopefully?)