Now that the weather is warming up it is time to tackle my A/C issue. Bought a 2000 XK8 last December with numberous little, and some not so little, problems. This weeks entertainment is the A/C.

The compressor clutch engages so there must be enough freon to activate the low pressure sensor. But at 650g total charge weight the system is really small compared to most cars I have worked on. I would therefore understand how even a small loss of refrigerant would significantly compromise the cooling capability of the system.

I had hoped to be able to 'top off' the A/C system with R134 by observing the low side pressure. Various systems have different low side specifications of usually from 0 lbs/square inch to a few (10 -20) pounds.

Just need to know what that number is for a correctly functioning system.

 

Hope this helps..

FOR AUTO AIR CONDITIONING R134a SYSTEMS:
At IDLE - Condenser inlet temp 170 to 180, Condenser Outlet temp 135 to 150 (usually a 30 to 40 degree drop in temperature across the Condenser), Evaporator Outlet temp 45 to 55, Compressor Suction temp 60 to 70 (usually a 15 to 20 degree drop in temperature from the evaporator outlet to compressor suction port). With the engine IDLING, you want to adjust the charge so the line at the Compressor suction port is about 10 to 20 degrees WARMER than the Evaporator Outlet pipe, and with the engine running at 1500 to 1800 rpm, you want the line at the Compressor suction port to be about 2 to 10 degrees WARMER than the Evaporator Outlet pipe.
At 1500 RPM - Condenser inlet temp 190 to 200, Condenser Outlet temp 135 to 155 (usually a 40 to 60 degree drop in temperature across the Condenser), Evaporator Outlet temp 45 to 55, Compressor Suction pressuretemp 55 to 60 [usually a 7 to 12 degree of Superheatfrom the evaporator outlet to compressor suction port (Saturation temp vs Evaporator outlet temp)].
At 90 degrees ambient, for R134a systems, look for about 200- 220 Pressures on the high side and about 25-30 Pressures on the low side at idle, and at 1,500 RPM look for about 220- 230 Pressures on the high side and about 20-27 Pressures on the low side.

 

PE R F EC T ! ! !

 

seals around the compressor leak and at the firewall.. and condensors do too.

 

I found another source of information elswhere. Everyone might want to BOOKMARK the following links as they have the best single source of information, not only for the A/C but everything aboutthe XK* I have found.

The site is not selling anything and is a collection of a hobbyist that loves his Jags.

Home page: http://www.blackriveroutdoors.com/XK8/JaguarXK8.htm

A/C page: http://www.blackriveroutdoors.com/XK...4/ACSystem.pdf

tp

 

I having problems opening the folders.....Indiacates File damaged cannot repair file.... What am I doing wrong? Look like good info!

 

I found the A/C one damaged, emailed the site owner and he reinstalled it. I down loaded it so I can email it to you if you are interested. Actually I downloaded all of them to my computer in case the site ever went away. All of the documents are real Jaguar Technical References.

 

I got the gauges and R134 out today and found thesystem was essentially empty. So much for my comment that the pressure sensor might affect the compressor clutch. The clutch was engaged and there was no measurable pressure in the system. Also no code reported on recent dealer scan although I didn't specifically ask them to look at the A/C. That day's problem was elswhere.

Would a dealer tech normally look at all codes if they connected their system up? I don't have any choice on by OBD II. It just lists what's there.

Now looking for leaks.

 

The leak is likely from the evaporator. If you have leak detector (electronic) put a/c on low with full charge and stick it in the right center vent. This will tell you.
Have also seen receiver/drier leak. Also the charge valves. In fact....I have seen every part of the a/c system leak except for the one hose to the condensor from receiver...lol
Let us know how it works out.
Normally we only look for the codes in modules related to your complaint.

 

cuz you live in florida. you guys do evaporatores like crazy... a/c alday everyday .not so many here.. ive done a couple on xk's

 

I probably do 2 a week along with everyone else. Can't remeber the last day I had with no a/c complaint.