Air conditioning noises?

[Pyromaniac1992]

Hi!

This may be the wrong thread I’m not sure, but wondering if I can get a little help.

Basically when my air con is turned on and I start up the car there’s a kind of hissing noise lasts only 2 seconds max, and then on my two central fans there doesn’t seem to be much cold air coming through but the side fans seem to work just fine.

If I turn the air con off, and back on again it seems to fix that problem...

Also when I turn the engine off I can hear a really faint kind of rattling noise not really sure how to describe it.. almost like air is been slowly released?

Any ideas on what could be wrong?

Thank you for any advice!

[gizlaroc]

What car? age?

Some do this when they are a bit low on the gas.

[Pyromaniac1992]

It’s a c4 cactus just turned 3 years old, did put it through a full service back in January too

[gizlaroc]

I would get it into Citroen for a bit of goodwill then.

[Justin S]

Refrigerant noises are common. Its usually just the refrigerant equalising pressure through the valve/ system when you turn it on or off. If you were short of refrigerant, usually you will have a continual hissing noise / compressor and condenser fans ( under the bonnet) switching on and off or nothing happening at all.
As for the other issues, can't help on that.
( I am an air con engineer)

[Peter3442]

I know nothing about Citroen, but are there any pneumatic valves controlling/directing the flow of air? If so, it may be part of the system working normally or showing early signs of failure.