Was driving out tonight with the climate control set at 23 degrees on auto.

Then I hear a hissing sound which lasted about 3 seconds like something was purging.

This happened again a couple of minutes later and so on every few minutes.

Any ideas?

Just had a/c serviced and re gassed. Guy said pressure was all good no leaks etc?

Thanks

Darren.

 

Unless it's a snake, no.

I wonder if a blocked evap housing might cause it? When was the cabin (aka pollen) filter last changed?

 

Lol thanks jagv8

Pollen filter was changed a month ago by myself.

 

My way of finding a noise is to have a helpful passenger who moves around to get nearer to it and try to figure it out. Putting the windows down helps but is cold at the moment.

 

This noise comes from the cabin. Sounds like the footwell.

Ill re phrase the hissing though. It more sounds like for 3 seconds the HVAC is blowing air at a higher pressure.

Could it be doing this to keep the temperature constant

If it was a leak surely the re gas guy would have picked it up?

 

Darren, I believe that noise is the AC system "cycling" circulating the freon to keep those seals from drying out - I have the same noise when my climate control is set to "auto" or when the "ac" button is lit - what you can do is press the AC button off and you will notice the hiss noise go away. And BTW - my AC system is fully charged and operational.

So, I don't think you have anything to worry about.

 

Thanks abonano.

The hiss I have located to somewhere up in the drivers footwell. Seems to blow hot air fine from all vents.

Ran ac on lo for 5 mins and it was cold on all sides.

And the hiss isn't permanent whic is strange. So hope your right buddy.

 

Abonano can you hear the cycle or hiss over your radio!

And does it come from the footwell drivers side UK in my case

 

Yes, if the radio is not blasting.

Did you turn the climate control on and turn the A/C off yet? If not, please do so and report back wit yur findings.

 

Ok I will try that tonight.
I'm guessing it can not be on auto right? As this switches Ac on.

 

Ok turned the Ac off with heat set at 23 degrees and the schhhhhhh noise stops

Turn a/c back on and schhhhhhh comes back.