My Jaguar XJS V12 1980 model has poor cooling in the A/C. I have had the compressor, drier, condenser, expansion valve and evaporator replaced. At startup from cold, the air is about 40F, but as soon as the condenser warms up, it goes to nearly 50F.

When I compare the hand-felt temperatures along the cycle with those on my other vehicles, I find:
1. The discharge from the compressor is very hot, too hot to touch on the Jag. I would guess above 180F, but I can just hold my hand on the other vehicles, about 120F, I think.

2. The condenser discharge temperature is still very hot, though I can just about hold my hand on it, perhaps 120F or more while on the other vehicles, the condenser discharge temperature is barely above my hand temperature.

3. The temperature at the low pressure filling point just before the compressor is cool, but not cool enough to condense water from the air on the Jag, but is cold and cold enough to condense water from the air on the other vehicles.

Can you suggest a cause? My guess is a blockage or restriction somewhere producing a high back pressure.

The original refrigerant was R-12, but this is illegal in Australia, so it was converted to R134A.

Ken Bilston

Do you
have the same problem?
Monday, November 26th, 2007 AT 6:49 PM

1 Reply

  • 31,765 POSTS

G'Day Ken.

You will need to have the High & Low pressures read & recorded so we can establish what is going on. I have had mixed results with R134A It may be a problem in the compressor, but a pressure reading will help.

Mark (mhpautos)

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Monday, November 26th, 2007 AT 7:58 PM

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