Aircon pressure.

[mjverdeyen]

Hi,

Does anyone know what the pressure should be on my gauge for the refrigerant in my XE aircon system? I mean when the engine is not running. When I switch the engine on the pressure shown on my gauge drops. What should the pressure be when the engine is running?

I mean in psi.

Thanks,

Martin Verdeyen.

[andypryce]

Hi Martin

Not sure specifically for the XE, but I assume they are all the same? For my XK8 the pressure with the engine running and aircon running on full, ie to lowest temp you can set, should be between 25-40psi. Pressure will be higher with engine off.

[mjverdeyen]

Hi Andy, Thanks for your reply.

The pressures when not running and then when running appear to be within the correct margins but I'm not sure the system is running cool enough. On my gauge the pressure is at the top of the 'green' when not running and then drops down when running, which I think is normal. However, if I leave the engine running for a while the pressure drops down almost to nothing. The strange thing is that when I switch the engine off and try again later the pressure appear to be perfectly OK again. Is the pressure supposed to drop down dramatically when the engine has been running for a while?

I know I shall have to take the car in to be checked, but I had a very bad experience with a so called Aircon expert with a previous Jag I owned and so I want to have an idea what is wrong before I have someone look at it.

Martin.

[Marineng]

Hi Martin
I presume you can only see the reading on the low pressure side of the system?

How old is the car and is it running on the R-134a refrigerant or the newer R-1234yf?

I am more used to marine and idustrial refrigeration systems but from your decription it seems like something is causing an obstruction on the HP side and therefore the gas does not circulate freely back to the LP side of the system, when it is running but given time the pressure can then equalize. If moisture has built up in the system and it freezes that could restrict the flow of gas as could a blocked dryer.

I agree that going to a professional aircon specalist armed with some searching questions will show that you can keep a close eye on the work. The important issue these days is that professionals are conforming to the f-gas regulations relating to qualifications and working practices.

I hope this helps - good luck.

Kind regards
Paul

[mjverdeyen]

Hi Paul,

The car is 4 years old, it uses R1234yf gas. The car has only 18,000 miles on it and is in perfect condition apart from the aircon system.

I bought and put into the system some R1234yf gas but I just realised that the STP tank of gas only holds 285 gm. The car apparently needs 550 gm. so maybe there isn't enough gas in the system. The pressure doesn't seem to be dropping as if there is a leak, so I'm thinking about buying more gas.

Thanks for your advice, I'll let you know what happens next.

Martin.

[andypryce]

As far as I know the pressure should not drop down that low when the engine is running, it does sound like you have a leak somewhere, a car of just 4 years old should not really have aircon problems at all. May be worth putting in some leak sealant, though I think I would be heading off to an aircon specialist. Messing around with it on a 23 year old car just keeps me amused, but if I had issues on my newer XF I would probably seek expert help.

[andypryce]

PS: daft question, but I assume your aircon is not working?

[mjverdeyen]

Hi Andy,

I know it is a long time since you last replied to me. My aircon wasn't working.

I did bite the bullet and took it into the Landrover /Jaguar dealer in Nelson. They checked and regassed the aircon system, they found no leaks and also ran a full health check on the car. There were no other faults found and when I picked it up the aircon was working perfectly. So far it still is (over a week later.)

It cost £149.00. Which is not much more than I paid for the DIY kit. I spoke at length to a member of staff at the garage, he assured me that everything was fine.

I'm keeping my fingers crossed but perhaps I should have just taken it into them in the first place?

Martin.

[andypryce]

A good result, a car that young should hopefully not have leaks, so its a bit odd it was low? I guess see how it goes, I used a much cheaper kit from amazon:

https://smile.amazon.co.uk/Aircon-Condi ... 215&sr=8-4

Dead easy, you can get a more expensive one with sealant too.

[Marineng]

Hi Martin,
It is really good news that the main dealer has come up trumps - the right service and the right time and at the right price - a note for all main dealers, it's not magic, just good business sense.

Thank you for sharing the update with everyone - it is much appreciated.

Kind regards
Paul