faulty ac unit

[alan williams]

Hi when my heater/ac unit is switched on I get a rumbling noise that keeps pace with the engine revs it makes the car sound very rough I have recharged the a/c and the pressure is staying constant but it is not cooling I am thinking this could be a fault in the compressor,if anyone can offer any advice on where to start looking I would be very grateful CHEER AGW.

[T-Cut]

Possibly the electric clutch on the compressor pulley has failed leading to the noises you get when the A/C is switch on. It's driven by the auxiliary drive belt. If that's what the problem is, I don't think the clutch is a separate item. You'll probably require a replacement compressor. Very expensive as OEM retail, but you can get them on eBay for less than £100. For example: http://shop.ebay.co.uk/?_from=R40&_t...+75+compressor

TC

[baxlin]

TC, or anyone, perhaps you could comment on my similar "problem", if you wouldn't mind.

I also have an engine-speed-matching noise, sounds almost like a dry bearing, when the aircon's on (and the radio's not on!), which disappears when the aircon's off. I can't remember if it's also there in Econ mode.

I've had the various belts changed (diesel car), and have no other problems with the aircon, it's cold, fan changes to High speed when first switched on if the car has been stood in the sun, etc, it's just this drone/whine.........

Thanks in advance

Malcolm

[Departed]

I too had a similar problem: rattle when AC on, stops when ECON selected.

That was a few weeks ago, and the car hasn't been run since whitsun due to being in bits.

Now, there's a significant problem with cooling: it chills a bit but not much. Clutch is coming in and fan starts.

The rattle made me think the compressor was on it's last legs, and this seems to confirm it. Shall be changing compressor and condensor as soon as I can find somewhere local that will degass, and regas for a sensible fee.

[T-Cut]

Originally Posted by baxlin

I also have an engine-speed-matching noise, sounds almost like a dry bearing, when the aircon's on (and the radio's not on!), which disappears when the aircon's off.

Sounds like a similar issue with the compressor/pulley clutch.

TC

[T-Cut]

Originally Posted by lowedb

Shall be changing compressor and condensor as soon as I can find somewhere local that will degass, and regas for a sensible fee.

KwikFit have a 'colder or your money back' guarantee for aircon systems. Costs around £40 I understand.

TC

[courier118]

I had mine done at KwikFit the other day......£44.95 or £64.90 with a de-bug.Took about an hour and my car was definately cooler afterwards

[Jules]

Originally Posted by baxlin

TC, or anyone, perhaps you could comment on my similar "problem", if you wouldn't mind.

I also have an engine-speed-matching noise, sounds almost like a dry bearing, when the aircon's on (and the radio's not on!), which disappears when the aircon's off. I can't remember if it's also there in Econ mode.

I've had the various belts changed (diesel car), and have no other problems with the aircon, it's cold, fan changes to High speed when first switched on if the car has been stood in the sun, etc, it's just this drone/whine.........

Thanks in advance

Malcolm

Hi Malcolm & Alan
I've cured a few of these compressor noises by getting my local AC specialist to come & add some proper oil into the system.
9 times out of 10 it cures the noise.

If noise persists afterwards, compressor may have overheated and suffered damage with a cooling fan problem in the past or may simply be worn.
Cooling Fan must be running when compressor is.

[ChristopherD]

Hi Jules,

Originally Posted by Jules

I've cured a few of these compressor

Can I please ask what sort of noises you've cured? My compressor (I think!) is making a horrendous knocking noise, but not constantly and only between certain rev ranges?!

Cooling doesn't seem very good at all, in fact probably getting worse, and doesn't seem to work at all when sitting stationary (even though the engine fan is spinning).

I'm reluctant to spend £45 - £65 on a re-gas only to find the compressor is completely shot! Car was registered early 2000 and so getting on a bit.

All comments appreciated.

Many thanks,

Chris

[baxlin]

Thanks Jules, when I bought the car 3 years ago, I knew the square root of not a lot about it (this club didn't exist, and I'd not found .org), and several months into ownership it suddenly overheated, and at that point I realised the fan was shot. How long it had been bust, I don't know, but your diagnosis seems not far wrong.

Malcolm