V50 AC : V50 aircon compressor question

[Jarndyce]

Simple question for V50 owners:
When you turn the a/c on, does the compressor run all the time, or does it kick in and out as required?

I've had trouble with my a/c lines freezing, then presumably the evaporator freezing up and reducing the airflow.
I've had the evaporator temp sensor replaced, and I *think* it's now ok, but the compressor does appear to run constantly, unless I turn the a/c off, in which case the clutch disengages.

Just want to check if the compressor should run constantly.

Thanks

[cheshired5]

Originally Posted by Jarndyce

SJust want to check if the compressor should run constantly.

No it shouldn't.
That's why it's fitted with a clutch.

[Jarndyce]

Originally Posted by cheshired5

No it shouldn't.
That's why it's fitted with a clutch.

Thank you for your reply, but are you certain of this? Is this what yours does?

I believe some cars have a variable displacement compressor which is designed to run constantly. In that case, the clutch is just to turn the a/c on and off.

[cheshired5]

Originally Posted by Jarndyce

Thank you for your reply, but are you certain of this? Is this what yours does?

I believe some cars have a variable displacement compressor which is designed to run constantly. In that case, the clutch is just to turn the a/c on and off.

My main ac pulley turns constantly via the auxiliary belt then the clutch pulls in and turns as and when required. When it's not needed, the clutch plate stops as the main pulley continues.
With the ac turned on, the clutch doesn't constantly spin as that depends on the temperature selected in the cabin and other factors like ambient outside temperature and engine load.
Admittedly I don't know for certain that's how yours is too so hopefully a fellow owner or expert can confirm.....

[Jarndyce]

Thanks.
Yes, I need someone else with a 2008 V50 with auto climate control that can give me a definitive answer.

Anyone...?

Different cars behave differently. We have a 2005 Clio, and on that the compressor kicks in and out as needed, whilst my Audi TT runs all the time.

[Welton]

I would say that your compressor should be typical of the model range and click in/out regularly to maintain gas pressure in the system. If a compressor appears to run 'flat out' it's normally a sign of low gas and is scavenging on the low pressure side; often accompanied by a grumbly/whirring sound and poor temperature at the outlets (target temperature is between 5 and 8 deg C).

If you haven't had an a/c service and regass for a while I would consider that first and go from there.

[Jarndyce]

Originally Posted by Welton

I would say that your compressor should be typical of the model range and click in/out regularly to maintain gas pressure in the system. If a compressor appears to run 'flat out' it's normally a sign of low gas and is scavenging on the low pressure side; often accompanied by a grumbly/whirring sound and poor temperature at the outlets (target temperature is between 5 and 8 deg C).

If you haven't had an a/c service and regass for a while I would consider that first and go from there.

Thanks.
Replacing the evaporator temp sensor had made a difference - it no longer simply blows freezing cold when the a/c is on, but the pipes are stilling icing up.

[alfadave11]

Originally Posted by Jarndyce

Thanks.
Replacing the evaporator temp sensor had made a difference - it no longer simply blows freezing cold when the a/c is on, but the pipes are stilling icing up.

do you know if anyone has regassed this system to your knowledge ? as if system hasn't got correct quantity in the system ie its over gassed it can lead to your problem

[alfadave11]

ive read your previous posts and ive come to conclusion that they just want to read fault codes to determine your problem .....that works if your system is set as per factory ....my question is to you regards your ac is ....do you know if they had ac equipment and if they know how much gas in system ...this ranges between 500 and 550 grams if the system is over gassed even by 50 grams your ac will play silly buggers between low side and high side and can induce ac to continuously run and ice up

[Jarndyce]

Originally Posted by alfadave11

ive read your previous posts and ive come to conclusion that they just want to read fault codes to determine your problem .....that works if your system is set as per factory ....my question is to you regards your ac is ....do you know if they had ac equipment and if they know how much gas in system ...this ranges between 500 and 550 grams if the system is over gassed even by 50 grams your ac will play silly buggers between low side and high side and can induce ac to continuously run and ice up

Thank you for taking the time to read my posts.
I agree that they've had a typical "plug it in and check the fault codes" approach.
My next step is to get the system looked at by someone who really understands a/c systems and has the correct equipment. (This isn't as easy as I anticipated. Most places just seem to offer re-gassing and "never heard of pipes icing...)

In the meantime, could running the a/c possibly damage the system?