Air Con Hissing Sound

[MorroN]

Hi Guys,

Flicked on the A/C for the first time in a while yesterday and I noticed it was making a weird constant hissing sound, almost like letting down someones tyres.

Definitely only happens when the A/C is on and I think I can hear the engine revs changing when the compressor clicks in.

any ideas?

 

[charltjr]

Probably low on refrigerant - the hissing is it moving gas around the system where it should be liquid.

 

[Rich-D]

As above, the system needs topping up.

 

[Crayola]

Snake caught in the rad

 

[JackJack]

Get it checked for leaks first.

The revs changing is normal.

 

[MorroN]

Probably low on refrigerant - the hissing is it moving gas around the system where it should be liquid.

Nice one, google suggested the same. Will book it in for a check/ re gas

 

[MorroN]

Get it checked for leaks first.

The revs changing is normal.

Will do.
I know, I just meant that the AC clutch was still engaging

 

[Rich-D]

When you get an aircon service, they will remove all the old refrigerant, hold the system under vacuum for a certain amount of time to check for leaks, then add the correct amount for the system.

They all lose a small amount per year, there's an acceptable leakage rate, so eventually they do need refilling, that's perfectly normal.

 

[MorroN]

Got it refilled and the noise has now gone and the AC is freeeeezing! Thanks all

£37 Groupon for ATS Euromaster at the moment fyi