75 cdti aircon compressor cutting in and out?

Teranchelope · 8th August 2020, 16:14

My compressor clutch is hopping on and off and aircon not getting very cold even after regas?
Gas seems to leak out over couple of months.
Where's the temp sensor for aircon cabin internal temp and would it be a bad compresdor/clutch or just dodgy electrical connection like on airbag conn's under seats?

SD1too · 8th August 2020, 16:54

Hello Richard,

Is your radiator fan running continuously?

Simon

COLVERT · 8th August 2020, 20:48

Probably just about to run out of gas again.--

It should have been dye tested before being re-filled the last time.

Pointless filling a system that's not been tested as you are beginning to find out.---

Teranchelope · 8th August 2020, 22:34

Just had it filled. They put dye in but said after 25 minutes detected no leaks? Have uprated fan condenser which works fine. Was okay before re-gas but never got ideally cold in cabin as my old 03 cdti did. Wonder if the electrical connector is dodgy in these high temperatures? Car hunts when driven or idling when compressor clutch cuts in. Cuts in and out on idle.

SD1too · 9th August 2020, 07:30

Hello Richard,

The compressor will disengage if the refrigerant pressure is either too low or too high. Call out a self employed mobile air conditioning specialist who can monitor these pressures and work out the cause. It could be many things. If necessary, he can extract your refrigerant charge and weigh it to find out if you've lost any.

The engine hunting is likely to be a tuning issue. The diesel has more than enough torque to drive the compressor effortlessly at idle.

It's good practice to run the air conditioning regularly throughout the year to keep the seals lubricated and in good condition. Loss of gas is usually the result of infrequent or no use.

I hope that this helps.

Simon

strand1988 · 9th August 2020, 08:10

I had a similar issue recently, turns out the compressor was completely shot. My car is an 02 with 230,000ish on the clock, when the compressor was running you could feel a rhythmic vibration through the entire car and the engine would idle rough. Eventually, there was a loud squealing from the compressor and a nasty smell of rubber.

I replaced it with a re-manufactured part for £95, plus a new belt and idler. I also changed the condenser and a worn A/C pipe. Nearly 4 weeks later and all is well, nice cold A/C and no vibration.

It might be worth checking your A/C pipes for wear in the common places - behind the rad where the PAS pipe sits, top of the engine where it can rub on the bonnet and next to the washer bottle.

SD1too · 9th August 2020, 11:19

Quote:

Originally Posted by Teranchelope

Car hunts when driven or idling when compressor clutch cuts in.

Hello again Richard,

Thanks to Strand1988 for his post which has reminded me of a problem which could be relevant here. The composite crankshaft pulley on the diesel engine is susceptible to failure. When this happens, the additional load when the air conditioning compressor engages can result in vibration. This is often misdiagnosed as a faulty compressor. So Richard I'd recommend that you check the condition of your crankshaft pulley. There's lots to read on the forum about it!

Simon

Teranchelope · 9th August 2020, 13:25

Thanks! Exactly what I am experiencing! New compressor sooo expensive! Noisy rattle heard too. I think after putting in sealant and getting a recharge the pressures were upped' and it has finally given in! I have a spare (radiator) condenser and getting new drive belts. I had the problem after spraying old belts with Belt rejuvenation' Maybe they have stretched a bit and are slipping too?
Better get a re-con compressor and do it all at same time as will lose the gas!

SD1too · 9th August 2020, 14:02

Richard, beware of spontaneous purchasing of expensive parts!

You've reported that:

Your compressor clutch is cutting in and out, even after a re-charge.
You've sprayed the drive belts with a magic potion.

Supposing the belt tension is incorrect, particularly after the spray, and as a result the compressor is not maintaining a suitable pressure. The trinary switch would then disable the compressor until the correct belt tension was restored.

If I were you I would replace the belt first, on its own, and see what happens. You stand to save money if that is the problem and you've lost nothing if it isn't.

By the way, don't put sealants in your air conditioning system. They can interfere with moving parts and cause you more problems.

Good luck with it.

Simon

strand1988 · 9th August 2020, 14:15

If you do end up replacing the compressor I purchased a re-manufactured one for £95 - excellent quality and has so far performed faultlessly. Also be aware that diesel and petrol compressors have different pulleys. The diesels have 5 groves, I believe the petrol has 6.

Its interesting that you say it was worse after the re-charge - mine did exactly the same thing.

I was also recently told by an A/C technician that sealant used in the system would not affect the moving parts in the compressor

8th August 2020, 16:14	#1
Teranchelope Regular poster Rover 75 Facelift 54 plate saloon Join Date: Feb 2016 Location: Pulborough Posts: 70 Thanks: 15 Thanked 4 Times in 4 Posts	75 cdti aircon compressor cutting in and out? My compressor clutch is hopping on and off and aircon not getting very cold even after regas? Gas seems to leak out over couple of months. Where's the temp sensor for aircon cabin internal temp and would it be a bad compresdor/clutch or just dodgy electrical connection like on airbag conn's under seats?

8th August 2020, 16:54	#2
SD1too Doesn't do things by halves Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model. Join Date: Mar 2007 Location: Former Middlesex Posts: 20,342 Thanks: 1,587 Thanked 3,749 Times in 3,181 Posts	Hello Richard, Is your radiator fan running continuously? Simon __________________ "Whatever is rightly done, however humble, is noble." Sir Henry Royce.

9th August 2020, 07:30	#5
SD1too Doesn't do things by halves Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model. Join Date: Mar 2007 Location: Former Middlesex Posts: 20,342 Thanks: 1,587 Thanked 3,749 Times in 3,181 Posts	Hello Richard, The compressor will disengage if the refrigerant pressure is either too low or too high. Call out a self employed mobile air conditioning specialist who can monitor these pressures and work out the cause. It could be many things. If necessary, he can extract your refrigerant charge and weigh it to find out if you've lost any. The engine hunting is likely to be a tuning issue. The diesel has more than enough torque to drive the compressor effortlessly at idle. It's good practice to run the air conditioning regularly throughout the year to keep the seals lubricated and in good condition. Loss of gas is usually the result of infrequent or no use. I hope that this helps. Simon __________________ "Whatever is rightly done, however humble, is noble." Sir Henry Royce.

9th August 2020, 08:10	#6
strand1988 Avid contributor Rover 75 Tourer Join Date: Jul 2013 Location: Hertfordshire Posts: 133 Thanks: 38 Thanked 76 Times in 13 Posts	I had a similar issue recently, turns out the compressor was completely shot. My car is an 02 with 230,000ish on the clock, when the compressor was running you could feel a rhythmic vibration through the entire car and the engine would idle rough. Eventually, there was a loud squealing from the compressor and a nasty smell of rubber. I replaced it with a re-manufactured part for £95, plus a new belt and idler. I also changed the condenser and a worn A/C pipe. Nearly 4 weeks later and all is well, nice cold A/C and no vibration. It might be worth checking your A/C pipes for wear in the common places - behind the rad where the PAS pipe sits, top of the engine where it can rub on the bonnet and next to the washer bottle. Last edited by strand1988; 9th August 2020 at 08:13..

9th August 2020, 14:02	#9
SD1too Doesn't do things by halves Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model. Join Date: Mar 2007 Location: Former Middlesex Posts: 20,342 Thanks: 1,587 Thanked 3,749 Times in 3,181 Posts	Richard, beware of spontaneous purchasing of expensive parts! You've reported that: Your compressor clutch is cutting in and out, even after a re-charge. You've sprayed the drive belts with a magic potion. Supposing the belt tension is incorrect, particularly after the spray, and as a result the compressor is not maintaining a suitable pressure. The trinary switch would then disable the compressor until the correct belt tension was restored. If I were you I would replace the belt first, on its own, and see what happens. You stand to save money if that is the problem and you've lost nothing if it isn't. By the way, don't put sealants in your air conditioning system. They can interfere with moving parts and cause you more problems. Good luck with it. Simon __________________ "Whatever is rightly done, however humble, is noble." Sir Henry Royce.

8th August 2020, 20:48	#3
COLVERT This is my second home R75 Saloon. Join Date: Feb 2009 Location: France/or Devon. Posts: 14,003 Thanks: 3,851 Thanked 2,167 Times in 1,816 Posts	Probably just about to run out of gas again.-- It should have been dye tested before being re-filled the last time. Pointless filling a system that's not been tested as you are beginning to find out.---

8th August 2020, 22:34	#4
Teranchelope Regular poster Rover 75 Facelift 54 plate saloon Join Date: Feb 2016 Location: Pulborough Posts: 70 Thanks: 15 Thanked 4 Times in 4 Posts	Just had it filled. They put dye in but said after 25 minutes detected no leaks? Have uprated fan condenser which works fine. Was okay before re-gas but never got ideally cold in cabin as my old 03 cdti did. Wonder if the electrical connector is dodgy in these high temperatures? Car hunts when driven or idling when compressor clutch cuts in. Cuts in and out on idle.

9th August 2020, 13:25	#8
Teranchelope Regular poster Rover 75 Facelift 54 plate saloon Join Date: Feb 2016 Location: Pulborough Posts: 70 Thanks: 15 Thanked 4 Times in 4 Posts	Thanks! Exactly what I am experiencing! New compressor sooo expensive! Noisy rattle heard too. I think after putting in sealant and getting a recharge the pressures were upped' and it has finally given in! I have a spare (radiator) condenser and getting new drive belts. I had the problem after spraying old belts with Belt rejuvenation' Maybe they have stretched a bit and are slipping too? Better get a re-con compressor and do it all at same time as will lose the gas!

9th August 2020, 14:15	#10
strand1988 Avid contributor Rover 75 Tourer Join Date: Jul 2013 Location: Hertfordshire Posts: 133 Thanks: 38 Thanked 76 Times in 13 Posts	If you do end up replacing the compressor I purchased a re-manufactured one for £95 - excellent quality and has so far performed faultlessly. Also be aware that diesel and petrol compressors have different pulleys. The diesels have 5 groves, I believe the petrol has 6. Its interesting that you say it was worse after the re-charge - mine did exactly the same thing. I was also recently told by an A/C technician that sealant used in the system would not affect the moving parts in the compressor

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