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Old 26th May 2020, 15:09   #1
larryr123
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Default Air Con Compressor Replacement

Hi - I have a MGZT-T 2005 - with I think a seized aircon compressor.
It makes a growling noise when switched on, and goes off completely when deactivated.
I noticed clear, clean oil coming from under where the compressor is located for some time a year or so ago and I'm assuming that all the oil has drained out of the compressor causing the seizure/growling noise.
It happened some time after I had had the system regassed so maybe there was a leak that has forced the oil out, and possibly the gas, I'm not sure.
I live in Bedfordshire and used to get help from Phil in Olney who was great, but he decided to go to work full time and isn't taking on private work anymore.

If anyone is interested in this and can recommend a replacement please get in touch with a contact that I can reach you on.
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Old 27th May 2020, 09:03   #2
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Hi Larry,

I see that you have the diesel engine. When the air conditioning is activated the compressor places a significant load on the crankshaft pulley. As you probably know, this pulley (on the diesel) is susceptible to failure of the "rubber" parts. I strongly recommend that you turn your attention to this.

Regarding the "clean, clear oil" which you have noticed, if this had escaped from the compressor then:
  1. It should contain luminous yellow/green dye.
  2. The refrigerant gas would also have escaped giving you little or no cooling.
  3. With little or no refrigerant gas, the compressor clutch would not engage and you would not hear the growling noise, if the compressor was responsible.

Since you have not said that your air conditioning is no longer cooling, I am not convinced that your compressor is at fault.

Simon
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Old 27th May 2020, 09:17   #3
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Quote:
Originally Posted by SD1too View Post
Hi Larry,

I see that you have the diesel engine. When the air conditioning is activated the compressor places a significant load on the crankshaft pulley. As you probably know, this pulley (on the diesel) is susceptible to failure of the "rubber" parts. I strongly recommend that you turn your attention to this.

Regarding the "clean, clear oil" which you have noticed, if this had escaped from the compressor then:
Quote:
  1. It should contain luminous yellow/green dye.
  2. The refrigerant gas would also have escaped giving you little or no cooling.
  3. With little or no refrigerant gas, the compressor clutch would not engage and you would not hear the growling noise, if the compressor was responsible.
Since you have not said that your air conditioning is no longer cooling, I am not convinced that your compressor is at fault.

Simon
As above which Simon points out, some sort of visual sign should be there.

1

2

3

The above photos are of a MGZT V6 190 the car became a spares part, I did obtain another compressor but it never got fitted, and still remains in the shed
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Old 28th May 2020, 13:35   #4
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Hi Simon, Thanks for the response. Interesting, I can honestly say I didn't see anything green. The oil was more like a clean fresh oil, definitely not engine oil which is a little more on the black side at the moment.
I'm curious as to where the oil could have come from.

Is it likely that this is to do with the seals for the coley pulley and is this a pretty big job to have them replaced, or a new coley pully?

Typically if I continue to use the air con, what is the likely problem as I plan a trip to Cornwall and it's getting hotter of late.

Regards Larry
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Old 28th May 2020, 14:11   #5
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Simon, Just tried the car over a few miles with aircon on. The cab was getting cooler, proving your point. It's not as cold as I would have liked, but I only took it a couple of miles and it's a hot day so probably needs more time to clear the cabin.
I kept it running on the drive and coudln't hear the noise with air con still switched on. It is over a year ago since I used the aircon and noticed the noise, so maybe I need a longer run for it to kick in again.
If it is the Coley Pully, would it be advisable to change the water pump at the same time?
I'm in Bedford, so if you know anyone who would take it on, I'd be grateful.

Regards Larry
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Old 28th May 2020, 14:47   #6
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Default Air Con Compressor Replacement

Just change the crank pulley, no need to touch the water pump, you could always get a garage to remove the pulley then inspect it for wear it’s not a terrible job to do.

Speak to PhilT4 at souls of Olney, he will sort the issue for you.

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Old 29th May 2020, 16:31   #7
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had the exact same issue, as simon says, it was the crank pulley.
Even my mechanic originally thought it was the aircon compessor as it only made a noise when the aircon was on.
They finally found the pulley was the cause by putting a chalk mark on the outer and inner part of the crankshaft pulley and found they were seperating and moved.
The denso aircon units Rover used are very good quality units and rarely go wrong.
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Old 30th May 2020, 09:41   #8
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Lightbulb A tip for Larry

Quote:
Originally Posted by larryr123 View Post
It is over a year ago since I used the aircon ...
Here's a tip for future reference Larry. The seals in your air conditioning pipework joints require periodic lubrication by the oil circulating with the refrigerant gas. If the system isn't used for a long time they begin to dry out and shrink and some, or all of your refrigerant will be lost.

It's therefore a good idea to run the air conditioning regularly throughout the year. Remember that it is a wonderful tool during wet weather to keep your windows free of mist and condensation due to its dehumidifying action.
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