Aircon compressor... will low gas level cause damage?

[Robertb]

My car has got a leaky aircon low-pressure line which is booked in for replacement in a month or so. The low gas level is manifesting in a grumbly compressor, and wheezing noises (from the car, not me!) which went away when I had it regassed a while ago. However, it still produces chilled air and I can't see any sense in shelling out for an interim recharge before the system is drained for the repair.

Will the low gas level damage the compressor if I continue to use it? Just mindful of the hot weather incoming!

 

[Gazc2]

Pretty sure the compressor is controlled by a pressure switch so once the gas gets to a certain level the compressor won't kick in hopefully somebody can confirm this.

 

[Alex]

As above - there is a low pressure switch to prevent the compressor running dry. Main concern is low lubricant as that keeps the compressor oiled up. But if the pressure switch hasn't disabled the compressor clutch then you should be fine.

 

[Robertb]

Cheers fellas, hopefully it'll hang on in there :thumb:

 

[deMort]

The 996 a/c compressor has a switchable clutch on it .. this basically either drives the compressor with the clutch engaged or it doesn't ..

As such .. low gas , low pressure and the clutch will not engage so the compressor is not running .

The noise you have is due to the gas pressure being lower than what's required ..

It gets a bit complicated but a/c is basically about a gas turning to a liquid and back to a gas again .. this process absorbs heat ... transference from one body to another via temperature differential .. some long winded term anyways ..

The point at which the gas / liquid is converted is in the expansion valve .. with a low pressure it starts to convert in the wrong place which basically causes the noises we all know are a/c related and go with the a/c turned off .

Short answer as already said is you are fine to carry on .. bearing in mind you do have an a/c switch that will turn it off as well .


Ok .. my main reason for this post and not for you but the newer cars .. most 997,s onwards .. might be just G2 .. onwards .. can't remember there , i look at the compressor and know straight off .

These don't have a clutch .. they have a running ( variable speed ) and idle setting .. idle being something like 5 % which is almost off ... but not quite ..

lack of lubricant in one if these .. a long term leak that's never been addressed ..

Compressor will keep running albeit at idle .. it will seize .. it will pump metal throughout the entire a/c system and for me at least after having tried .. you won't be able to clean out the system ..

In short .. that's every single item related to the a/c that needs replacing .. ill guess at £9K perhaps ?

This system is called the swash plate type compressor .

 

[Robertb]

Thanks DeMort, that's reassuring. I will use sparingly if it gets too warm.

The issue with the newer cars sounds worrying... I've heard of similar issues with the battery cooling system on BMW i8.