Noisy Air Con

RoryRover · 20th April 2011, 19:42

Hello all

I have just joined the ranks of Rover 75 owners having just aquired a 2004 Connie SE diesel tourer.

As you may imagine I am exploring the joys of Rover 75 ownership and would appreciate some guidance on the air conditioning.

I have noticed that when I switch the air conditioning on, I get a whine which rises and falls with engine speed which is really noticable because the car is otherwise so quiet. It is not the blower fan - that stays constant with changes in engine speed.

The whine is very pronounced at tickover and just above but blends into the background when traveling over 30mph.

When the engine is ticking over, the whine disapears immediately if the Air con is switched off or if the "econ" mode is selected.

One final point - the car was serviced and the air con re-charged by the dealer before I took delivery.

Can anyone tell me if this "whine" is normal when the air con is operating - or otherwise what the problem might be ?

John Neal

T-Cut · 20th April 2011, 20:44

I'd suspect something in the drive train on the auxiliary belt. This includes the aircon compressor which freewheels on the belt until you press Auto/Aircon On. This activates the magnetic clutch on the compressor pulley and adds more load to the drive belt. Maybe the pulley or the belt tensioner is making the noise. Maybe the compressor is worn. This can happen if used too much with a failed cooling system. So, also ensure the slow speed radiator fan runs continuously while aircon is in Auto/On.

TC

Jules · 20th April 2011, 21:02

Yep as TC says
Classic case of a cooked compressor (due to failed cooling fan)
Fan must run whenever compressor is running.

In a few cases a degas/regas and addition of 30cc of PAG oil will cure a whining compressor so long as the cooling fan is in good order.

Good luck

bl52krz · 20th April 2011, 21:20

If your fan haspacked up, Jules is the man to see.

fse73549 · 20th April 2011, 22:46

Mine does the same, whines that goes up and down with the revs of the engine.
What sort of price are we looking at to do full regas with a bit of extra oil as if I have to replace the compressor it's over 500 quids worth. I can do a regas but my rig won't put oil in so would prefer someone who know our cars to do it.

RoryRover · 21st April 2011, 06:19

Hello All

Thanks for the advice you have given me - I really appreciate it.

I will be back in touch with the dealer (not very hopeful - I have just looked through the warranty guide he gave me, and it says I would have to pay extra to include the Air con system - not that he told me that !)

I would also be interested in how the oil would be added to the system - it has got to be worth a try !

John

20th April 2011, 19:42	#1
RoryRover Avid contributor Rover 75 Con SE CDTi tourer Join Date: Apr 2011 Location: Derbyshire Posts: 135 Thanks: 6 Thanked 0 Times in 0 Posts	Noisy Air Con Hello all I have just joined the ranks of Rover 75 owners having just aquired a 2004 Connie SE diesel tourer. As you may imagine I am exploring the joys of Rover 75 ownership and would appreciate some guidance on the air conditioning. I have noticed that when I switch the air conditioning on, I get a whine which rises and falls with engine speed which is really noticable because the car is otherwise so quiet. It is not the blower fan - that stays constant with changes in engine speed. The whine is very pronounced at tickover and just above but blends into the background when traveling over 30mph. When the engine is ticking over, the whine disapears immediately if the Air con is switched off or if the "econ" mode is selected. One final point - the car was serviced and the air con re-charged by the dealer before I took delivery. Can anyone tell me if this "whine" is normal when the air con is operating - or otherwise what the problem might be ? John Neal

20th April 2011, 21:02	#3
Jules This is my second home ZT 260 SE Twilight and 10 other 75 ZT's :O Join Date: Jan 2007 Location: Conwy NORTH WALES Posts: 11,094 Thanks: 512 Thanked 1,116 Times in 763 Posts	Yep as TC says Classic case of a cooked compressor (due to failed cooling fan) Fan must run whenever compressor is running. In a few cases a degas/regas and addition of 30cc of PAG oil will cure a whining compressor so long as the cooling fan is in good order. Good luck __________________ [SIGPIC][/SIGPIC] Newbies do now!! 1. Plenum drains..all 3 or 4 year dependent 2. Cooling fan..All speeds functioning 3. Bonnet cable divider block

20th April 2011, 21:20	#4
bl52krz This is my second home Rover 75 cdt club + Rover 2.5 KV6 Conni SE Join Date: May 2008 Location: Birmingham Posts: 11,397 Thanks: 6,587 Thanked 2,262 Times in 1,729 Posts	If your fan haspacked up, Jules is the man to see. __________________ Great Barr, Birmingham.

21st April 2011, 06:19	#6
RoryRover Avid contributor Rover 75 Con SE CDTi tourer Join Date: Apr 2011 Location: Derbyshire Posts: 135 Thanks: 6 Thanked 0 Times in 0 Posts	Noisy Air Con Hello All Thanks for the advice you have given me - I really appreciate it. I will be back in touch with the dealer (not very hopeful - I have just looked through the warranty guide he gave me, and it says I would have to pay extra to include the Air con system - not that he told me that !) I would also be interested in how the oil would be added to the system - it has got to be worth a try ! John

20th April 2011, 20:44	#2
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,753 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	I'd suspect something in the drive train on the auxiliary belt. This includes the aircon compressor which freewheels on the belt until you press Auto/Aircon On. This activates the magnetic clutch on the compressor pulley and adds more load to the drive belt. Maybe the pulley or the belt tensioner is making the noise. Maybe the compressor is worn. This can happen if used too much with a failed cooling system. So, also ensure the slow speed radiator fan runs continuously while aircon is in Auto/On. TC

20th April 2011, 22:46	#5
fse73549 The Best Car In The World Rover 75 Connie se Tourer Join Date: Aug 2009 Location: Bolton Posts: 215 Thanks: 1 Thanked 1 Time in 1 Post	Mine does the same, whines that goes up and down with the revs of the engine. What sort of price are we looking at to do full regas with a bit of extra oil as if I have to replace the compressor it's over 500 quids worth. I can do a regas but my rig won't put oil in so would prefer someone who know our cars to do it.