aircon pulley noise - Page 2

genpk · 14th November 2019, 02:42

switched aircon on just got the hose and spayed the idler pulley and indirectly the aircon unit and the loud noise goes so im thinking maybe its the idler pulley.
Goes alot quieter when the engine is reved then comes back at idle.
Aircon still nice and cold though.

Rich in Vancouver · 14th November 2019, 02:54

I have a similar noise on my V6 and have narrowed it down to the compressor. Everything has been replaced except the A/C compressor so that will be next if it gets any worse.
One question...On a ZT V6 do the bumper and radiator have to come off to change the compressor? It seems a bit tight under there to get it out any other way.

genpk · 14th November 2019, 03:20

does your noise only happen when the aircon is switched on? although i can faintly hear it still when off.
I have got it down to either the idler pulley or aircon compressor.
Im guessing either the load on the pulley changes when aircon is activated as when i lever on the pulley it does change the tone of the noise OR there is somthing going on in the clutch of the aircon compressor although its working and icy cold.
Im going to try the idler pulley first (cheap option first)

Rich in Vancouver · 15th November 2019, 00:46

Mine only happens with the A/C on and is quite noticeable. The idler was replaced in September when I did the timing belts along with the timing belt idler, tensioner pulley and water pump.(so it isn't them!)

genpk · 15th November 2019, 02:25

well seems my mechanic has diagnosed it as the air compressor.
Spray water onto the aircon clutch area and it changes, almost disappears.
Starting to also get a little of the pulley noise also when the aircon is off now as well.
Mechanics saying probably the bearings in the compressor.
Strange as it is the lowest km car out of all the 4 i own, never had this issue on any of the others.
Being as people want stupid money ($800 aud) for a new air compressor,
about half the cars value, i found a s/hand one out of a scrap car that has done
147k on it for a reasonable price.
After the price of the unit, fitting, re gassing etc probably about $600 aud with a bit of luck!!

genpk · 15th November 2019, 08:57

been doing a bit or research just in case the second hand one arrives and isnt great.
I see you can replace just the pulley and clutch at the front of the compressor which houses the front bearings if you want to disassemble it.
Anyone ever pulled the pulley etc off a denso aircon unit ?

SD1too · 15th November 2019, 09:32

Quote:

Originally Posted by genpk

Anyone ever pulled the pulley etc off a denso aircon unit ?

You'll need a specific service tool to release the shaft nut. I'd recommend that you find a company which repairs automotive air conditioning compressors and give the job to them.

Before you do that though, having released the ancillary drive belt, spin the clutch pulley by hand and listen for rough running. Also try to rock it from side to side to detect any bearing wear. It should be smooth, silent and tight.
If you apply 12v to the electrical connector the clutch will engage and you can then test the shaft bearings in the same way. You can do all this without having to discharge the refrigerant or remove the compressor from the car.

Simon

genpk · 15th November 2019, 09:53

thanks simon, spoke with local auto electric guys who reckon if the compressor is noisey when activated then the internals are probably gone.
Not sure how that works as its quiet when the compressor is not activated but starts squealing like a knackered pulley when the ac is on.
I think its the bearing behind the pulley and clutch as i spray degreaser and it goes quiet for a bit.
Got wait till 25th till the s/hand compressor arrives out of an 05 car being broken and hope it works.
New units are worth more than the car is !!

genpk · 17th November 2019, 11:30

Interesting, noticing when the car power steering is under load ie turning in a car park that there is a slight pulley noise even without the airconditioning on now.
Think it may be the main clutch bearing gone.

SD1too · 17th November 2019, 16:02

Peter,

Time for a quick reminder of what I said in post no. 4:

Quote:

Originally Posted by SD1too

... engaging the air conditioning compressor places a heavy load upon the engine so an increase in noise could be a lot of things ...

Your recent observation that the noise is now heard when the power steering operates ....

Quote:

Originally Posted by genpk

... when the car power steering is under load ... there is a slight pulley noise even without the air conditioning on ...

... places doubt on your theory.

Many people approach fault finding by convincing themselves that something must be responsible (usually a complex component), then try to make the evidence fit their firmly held belief. This can be an expensive mistake.

You're doing the right thing by keeping your eyes and ears open but try to keep an open mind too. I gave you a test procedure to lessen the risk of replacing the compressor then finding out that it wasn't that after all. Carrying that out will be more conclusive than endless speculation of what it might be.

Simon

14th November 2019, 02:54	#12
Rich in Vancouver Gets stuck in MG ZT-T Join Date: Jun 2016 Location: White Rock, BC on Canada's Pacific Coast Posts: 849 Thanks: 338 Thanked 367 Times in 210 Posts	I have a similar noise on my V6 and have narrowed it down to the compressor. Everything has been replaced except the A/C compressor so that will be next if it gets any worse. One question...On a ZT V6 do the bumper and radiator have to come off to change the compressor? It seems a bit tight under there to get it out any other way. __________________ ZT-T190, Anthracite, LHD, Left the Line on June 24, 2002, Sold new in Switzerland, spent time in Germany, Imported to Canada in September 2021

15th November 2019, 00:46	#14
Rich in Vancouver Gets stuck in MG ZT-T Join Date: Jun 2016 Location: White Rock, BC on Canada's Pacific Coast Posts: 849 Thanks: 338 Thanked 367 Times in 210 Posts	Mine only happens with the A/C on and is quite noticeable. The idler was replaced in September when I did the timing belts along with the timing belt idler, tensioner pulley and water pump.(so it isn't them!) __________________ ZT-T190, Anthracite, LHD, Left the Line on June 24, 2002, Sold new in Switzerland, spent time in Germany, Imported to Canada in September 2021

15th November 2019, 08:57	#16
genpk Posted a thing or two Rover 75 Saloon MGZT Join Date: Jul 2012 Location: Perth, AUSTRALIA Posts: 1,662 Thanks: 3 Thanked 461 Times in 299 Posts	been doing a bit or research just in case the second hand one arrives and isnt great. I see you can replace just the pulley and clutch at the front of the compressor which houses the front bearings if you want to disassemble it. Anyone ever pulled the pulley etc off a denso aircon unit ? Last edited by genpk; 15th November 2019 at 08:59..

14th November 2019, 02:42	#11
genpk Posted a thing or two Rover 75 Saloon MGZT Join Date: Jul 2012 Location: Perth, AUSTRALIA Posts: 1,662 Thanks: 3 Thanked 461 Times in 299 Posts	switched aircon on just got the hose and spayed the idler pulley and indirectly the aircon unit and the loud noise goes so im thinking maybe its the idler pulley. Goes alot quieter when the engine is reved then comes back at idle. Aircon still nice and cold though.

14th November 2019, 03:20	#13
genpk Posted a thing or two Rover 75 Saloon MGZT Join Date: Jul 2012 Location: Perth, AUSTRALIA Posts: 1,662 Thanks: 3 Thanked 461 Times in 299 Posts	does your noise only happen when the aircon is switched on? although i can faintly hear it still when off. I have got it down to either the idler pulley or aircon compressor. Im guessing either the load on the pulley changes when aircon is activated as when i lever on the pulley it does change the tone of the noise OR there is somthing going on in the clutch of the aircon compressor although its working and icy cold. Im going to try the idler pulley first (cheap option first)

15th November 2019, 02:25	#15
genpk Posted a thing or two Rover 75 Saloon MGZT Join Date: Jul 2012 Location: Perth, AUSTRALIA Posts: 1,662 Thanks: 3 Thanked 461 Times in 299 Posts	well seems my mechanic has diagnosed it as the air compressor. Spray water onto the aircon clutch area and it changes, almost disappears. Starting to also get a little of the pulley noise also when the aircon is off now as well. Mechanics saying probably the bearings in the compressor. Strange as it is the lowest km car out of all the 4 i own, never had this issue on any of the others. Being as people want stupid money ($800 aud) for a new air compressor, about half the cars value, i found a s/hand one out of a scrap car that has done 147k on it for a reasonable price. After the price of the unit, fitting, re gassing etc probably about $600 aud with a bit of luck!!

15th November 2019, 09:53	#18
genpk Posted a thing or two Rover 75 Saloon MGZT Join Date: Jul 2012 Location: Perth, AUSTRALIA Posts: 1,662 Thanks: 3 Thanked 461 Times in 299 Posts	thanks simon, spoke with local auto electric guys who reckon if the compressor is noisey when activated then the internals are probably gone. Not sure how that works as its quiet when the compressor is not activated but starts squealing like a knackered pulley when the ac is on. I think its the bearing behind the pulley and clutch as i spray degreaser and it goes quiet for a bit. Got wait till 25th till the s/hand compressor arrives out of an 05 car being broken and hope it works. New units are worth more than the car is !!

17th November 2019, 11:30	#19
genpk Posted a thing or two Rover 75 Saloon MGZT Join Date: Jul 2012 Location: Perth, AUSTRALIA Posts: 1,662 Thanks: 3 Thanked 461 Times in 299 Posts	Interesting, noticing when the car power steering is under load ie turning in a car park that there is a slight pulley noise even without the airconditioning on now. Think it may be the main clutch bearing gone.