Hissing from aircon

Simiewimie · Feb 21st, 2017, 10:56

Hi.

I'm hoping somebody may know what is causing the air-conditioning in my XC90 to hiss. it sounds as though it is coming from towards the back of the dash, at the foot of the windscreen. I can stop it by turning of air conditioning and it just being the fans, but I also noticed yesterday that it drops whilst accelerating past 2500 rpm.

Any ideas?
Many thanks.

Fliegenpilz · Jul 11th, 2017, 21:21

I got the same hiss. It sounds like a CD changer missing tracks or like tiny bubbles passing through the aircon pipes, a bit like a fridge. I have been to the garage 3-4 time son this and they took out the centre console and found that that a tiny rubber pipe that is connected to the aircon exchanger is supposed to direct cold air to the sensus display which needs cooling and they recon that is the source. Been waiting for a few weeks now for that part from Volvo and not even sure if that will solve it. I keep thinking it is to do with the refridgerant flow and bubbles. When I switch off the aircon it stops so definitely aircon and also definitely right behind centre console. Drives me nuts when driving.

XCF · Jul 11th, 2017, 21:50

I've got exactly the same so watching this thread with interest.

I wondered if a regas was an idea but it does blow cold...just noisy!

Acer · Jul 12th, 2017, 11:09

Quote:

Originally Posted by XCF

I've got exactly the same so watching this thread with interest.

I wondered if a regas was an idea but it does blow cold...just noisy!

How many miles have all your cars done? Interested to understand how much the air conditioning is likely to have been used, before this happened.

Simiewimie · Jul 13th, 2017, 13:19

Just to update:

I had the air-con re-gassed, and so far so good.

My XC90 has done 116000.

XJSDriver · Jul 13th, 2017, 17:29

In my experience this is likely due to the a/c gas getting low - the system leaks gas over time as the R-22 refrigerant molecules are small enough to escape through the hoses!
I have an XJS which has a very small leak and needs re-gassing every year as too small to find and lasts whole season; I know the gas is low as it hisses and gurgles. This is always in the evaporator which sits behind the dashboard in the heater box - this is the same design as most cars so if you are hearing a hiss behind the dashboard then my guess is you need a re-gas.

XCF · Jul 13th, 2017, 20:24

Mine has also done about 115k mikes (2010 car) so sounds like I need to get it regassed. Is Kwik-fit a safe enough choice here for a simple re-gas ?

XCF · Jul 22nd, 2017, 21:17

Took it to Kwikfit today. They said there was very little in it but when they re-gassed it they spotted an issue with the low pressure schrader valve leaking. They didn't charge me but now I have to try and fix that.
Does anyone know if it's worth trying to tighten the valve in if I buy the valve tool?

Also with the bonnet open there is a loud(ish) noise when I turn on the aircon. Are there any basic checks I can follow to work out what this is ?

Thanks

Feb 21st, 2017, 10:56	#1
Simiewimie Junior Member Last Online: Feb 6th, 2020 09:20 Join Date: Nov 2013 Location: Warwickshire	Hissing from aircon Hi. I'm hoping somebody may know what is causing the air-conditioning in my XC90 to hiss. it sounds as though it is coming from towards the back of the dash, at the foot of the windscreen. I can stop it by turning of air conditioning and it just being the fans, but I also noticed yesterday that it drops whilst accelerating past 2500 rpm. Any ideas? Many thanks.

Jul 11th, 2017, 21:21	#2
Fliegenpilz New Member Last Online: Oct 22nd, 2019 11:18 Join Date: Dec 2016 Location: London	I got the same hiss. It sounds like a CD changer missing tracks or like tiny bubbles passing through the aircon pipes, a bit like a fridge. I have been to the garage 3-4 time son this and they took out the centre console and found that that a tiny rubber pipe that is connected to the aircon exchanger is supposed to direct cold air to the sensus display which needs cooling and they recon that is the source. Been waiting for a few weeks now for that part from Volvo and not even sure if that will solve it. I keep thinking it is to do with the refridgerant flow and bubbles. When I switch off the aircon it stops so definitely aircon and also definitely right behind centre console. Drives me nuts when driving.

Jul 11th, 2017, 21:50	#3
XCF Master Member Last Online: Jan 7th, 2024 23:26 Join Date: Oct 2009 Location: UK	I've got exactly the same so watching this thread with interest. I wondered if a regas was an idea but it does blow cold...just noisy!

Jul 13th, 2017, 13:19	#5
Simiewimie Junior Member Last Online: Feb 6th, 2020 09:20 Join Date: Nov 2013 Location: Warwickshire	Just to update: I had the air-con re-gassed, and so far so good. My XC90 has done 116000.

Jul 13th, 2017, 17:29	#6
XJSDriver XJS Driver Last Online: Apr 22nd, 2024 23:00 Join Date: Apr 2017 Location: Hitchin	In my experience this is likely due to the a/c gas getting low - the system leaks gas over time as the R-22 refrigerant molecules are small enough to escape through the hoses! I have an XJS which has a very small leak and needs re-gassing every year as too small to find and lasts whole season; I know the gas is low as it hisses and gurgles. This is always in the evaporator which sits behind the dashboard in the heater box - this is the same design as most cars so if you are hearing a hiss behind the dashboard then my guess is you need a re-gas.

Jul 13th, 2017, 20:24	#7
XCF Master Member Last Online: Jan 7th, 2024 23:26 Join Date: Oct 2009 Location: UK	Mine has also done about 115k mikes (2010 car) so sounds like I need to get it regassed. Is Kwik-fit a safe enough choice here for a simple re-gas ?

Jul 22nd, 2017, 21:17	#8
XCF Master Member Last Online: Jan 7th, 2024 23:26 Join Date: Oct 2009 Location: UK	Took it to Kwikfit today. They said there was very little in it but when they re-gassed it they spotted an issue with the low pressure schrader valve leaking. They didn't charge me but now I have to try and fix that. Does anyone know if it's worth trying to tighten the valve in if I buy the valve tool? Also with the bonnet open there is a loud(ish) noise when I turn on the aircon. Are there any basic checks I can follow to work out what this is ? Thanks

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