S80: Information Aircon has a mind of its own.

[Vol S80 Lux]

Hello everyone.....I hope someone can help me out with some general information.

When I bought my s80 se lux, the aircon wasnt blowing cold air so I assumed it needed re-gassing. After I had that done last year at a cost of £49, the aircon worked fine for about a month and then got warm again. I thought there must be a leak in the system somewhere but by then the summer had gone and I put it off till this year.
I had it re-gassed at the same place this year and told them about it so they decided to put a dye in with the gas to see where the leak was. Now the aircon is getting warmer again but they cant find a leak. They've used a uv light to look at the aircon pipes but cant find anything so their only suggestion is that there isnt a leak but something else is the problem therefore it needs to go to an aircon specialist.

Heres the funny thing. If the outside temp is about 25 degrees or less, the aircon does come on and throws out some cold air. Not loads as a newly gassed system but just enough to keep you from sweating. But if the temp is any higher the air is just hot as though the aircon system isnt on.

So I spoke to an aircon specialist who said some cars a made like that. So the aircon doesnt come on if the outside temp is too high. Doesnt that defeat the purpose of having the aircon?
Surely that cant be right.

So my questions are does a high outside temp stop the aircon from working? If so, why?
Are there any easy methods of finding a leak or leak prone areas?
What do you guys suggest I do to get this issue resolved?

Thank you and sorry about the wall of text.

[cheshired5]

It sounds like the symptoms of the clutch gap issue.
Aircon works fine initially and you can see the compressor clutch engaging and spinning but as heat increases in the engine bay, so does electrical resistance and the strength of the electromagnet isn't enough to pull in the compressor clutch.

Your first job is to turn AC to minimum temperature, leave all windows open (and doors if practical) then look at the compressor clutch plate behaviour.
If it engages from a cold engine start then stops engaging when warm, it's almost certainly the clutch gap.

If warm air starts to enter the cabin and the AC clutch is engaging/disengaging on its own, it's likely low gas.

If you click on the link in my signature and scroll down, you'll find my free clutch gap fix video.

[Vol S80 Lux]

Thank you very much. The video is very useful even though my s80 is one model newer than the one in the video I assume the aircon clutch will be in the same place/same problem.


Iv also noticed that my feet get a lot of cold air from the aircon but the upper vents on the dash facing the driver arent up to scratch. Is that possible or am I being paranoid?

[apersson850]

You could have a combination of a fault in one of the vent motors and problems with cooling.

My current car, a 2012 model, hasn't had any AC issue yet (except a software upgrade which had a bug), but on my 850, I first had to remove shims in the compressor clutch, then replace the vaporizer module inside the dashboard due to a leak there.

[Laird Scooby]

Originally Posted by Vol S80 Lux

Thank you very much. The video is very useful even though my s80 is one model newer than the one in the video I assume the aircon clutch will be in the same place/same problem.


Iv also noticed that my feet get a lot of cold air from the aircon but the upper vents on the dash facing the driver arent up to scratch. Is that possible or am I being paranoid?

It's possible you have some dry joints on the vacuum solenoid block that directs the flaps to open/close to alter temperature and direction of flow. I had this on my 760 and it had been present for quite some time. As a result the previous owner had the evaporator (the air-con radiator that makes the incoming air cold in the heater box) removed in the false belief it was blocked. The symptoms are very similar to what you describe.

Also does your car have a pollen filter? If so and it's blocked that will prevent airflow through the heater and A/C system so the A/C will think it's cold but in reality it isn't.

[cheshired5]

Originally Posted by Vol S80 Lux

Iv also noticed that my feet get a lot of cold air from the aircon

With this extra information, it sounds as though the compressor is working fine so ignore my previous suggestion.

You could just need a CCM calibration, which takes a minute or so with Dice and Vida.

[Vol S80 Lux]

.

Ok so Iv looked under the bonnet at, what I think is the compressor clutch. Is it the pulley directly beneath the alternator?

Its spinning perfectly fine when cold and hot. Unless thats not it.

[Laird Scooby]

Unless i've totally misunderstood your question, it's doubtful. This might answer your question though :



The clutch assembly in on the driven end of the compressor between the compressor and the pulley.

[Vol S80 Lux]

Originally Posted by Laird Scooby

Unless i've totally misunderstood your question, it's doubtful. This might answer your question though :



The clutch assembly in on the driven end of the compressor between the compressor and the pulley.

Thanks this is useful. Ill have another look tomorrow and report back.

[Joe Harding]

Originally Posted by Vol S80 Lux

Hello everyone.....I hope someone can help me out with some general information.

When I bought my s80 se lux, the aircon wasnt blowing cold air so I assumed it needed re-gassing. After I had that done last year at a cost of £49, the aircon worked fine for about a month and then got warm again. I thought there must be a leak in the system somewhere but by then the summer had gone and I put it off till this year.
I had it re-gassed at the same place this year and told them about it so they decided to put a dye in with the gas to see where the leak was. Now the aircon is getting warmer again but they cant find a leak. They've used a uv light to look at the aircon pipes but cant find anything so their only suggestion is that there isnt a leak but something else is the problem therefore it needs to go to an aircon specialist.

Heres the funny thing. If the outside temp is about 25 degrees or less, the aircon does come on and throws out some cold air. Not loads as a newly gassed system but just enough to keep you from sweating. But if the temp is any higher the air is just hot as though the aircon system isnt on.

So I spoke to an aircon specialist who said some cars a made like that. So the aircon doesnt come on if the outside temp is too high. Doesnt that defeat the purpose of having the aircon?
Surely that cant be right.

So my questions are does a high outside temp stop the aircon from working? If so, why?
Are there any easy methods of finding a leak or leak prone areas?
What do you guys suggest I do to get this issue resolved?

Thank you and sorry about the wall of text.

Same for us during recent heatwave. Air con no good until outside temp fell below 28 or thereabouts.