Hissing coming from inside the dash?

**Garett** · Tuesday 3rd December 2013, 21:02

I have strange hissing/whooshing noise that comes when the AC is on. It seems to come and go in cycles but it always there pretty much whenever the AC is on.

Could it just be a simple case of needing a regas or is it likely to be something more serious?

**Harvey** · Tuesday 3rd December 2013, 22:12

That sounds normal the expansion valve will open close in this weather as the system is not working hard.
When you turn the engine off after the air con has been on you can still hear the liquid/gas pressure moving through the system.

**stephenevans99** · Tuesday 3rd December 2013, 22:20

Low on refrigerant I reckon.

**Garett** · Wednesday 4th December 2013, 09:34

Its been doing it since summer and has gradually got worse. It used to be every now and then butbit is now constant. I've had the car 3 years now and it didn't used to do it until summer wuen it was very hot in July. It still blows fairly cold though. ...

**Harvey** · Wednesday 4th December 2013, 16:37

Originally Posted by Garett

Its been doing it since summer and has gradually got worse. It used to be every now and then butbit is now constant. I've had the car 3 years now and it didn't used to do it until summer wuen it was very hot in July. It still blows fairly cold though. ...

Sounds like a service is required,sure the air con bods will manage to get you,have it been serviced in the time you had the car.
Best not to run it till it's been looked at just leave the air con switched off as you don't want to kill the compressor.

**Garett** · Wednesday 4th December 2013, 16:52

Ok nice one, it is due a service soon so I'll get them to have a look at the air con too. Hopefully there's no lasting damage to the compressor as I've still been using it while its been like that!

**Garett** · Saturday 4th January 2014, 18:49

Originally Posted by stephenevans99

Low on refrigerant I reckon.

Had the car serviced and they did the air con too. They topped up the gas and all is well now, thanks!

**LeeT5** · Saturday 4th January 2014, 19:10

Originally Posted by Harvey

Sounds like a service is required,sure the air con bods will manage to get you,have it been serviced in the time you had the car.
Best not to run it till it's been looked at just leave the air con switched off as you don't want to kill the compressor.

If the Aircon Gas is low the compressor will cycle more often (You'll hear it engage/disengage more often).

However, If the gas gets too low (not sure of the minimum pressure for the system to function) then the pressure switch will deactivate the compressor and prevent it from running. Therefore, you cannot kill a compressor if your system is very low or empty.

**Garett** · Saturday 1st February 2014, 11:56

Just for closure on this topic to help anyone searching in the future the air con gas was topped up and the sound went away, thats the sort of repairs I like, nice and simple!

**Harvey** · Saturday 1st February 2014, 12:18

Originally Posted by Garett

Just for closure on this topic to help anyone searching in the future the air con gas was topped up and the sound went away, thats the sort of repairs I like, nice and simple!

How much gas did they have to put in then ?.