2001 S Type 3.0 51,000 miles.

A/C cooling OK when moving with air flow in traffic. When not moving A/C temp inadequet-heats up ~10 deg F. Replaced fan module, no improvement. Engine temp normal under all conditions, not overheating. Fan function appears normal but symptoms seams to indicate not enough fan speed to cool A/c evaporator when vehicle stopped i.e. increase in A/C temp ~10 deg. I have replaced new AC compressor, dryer.
Does anyone have any suggestions.

Additional info...
1. cleaned condensor coils...no change. (however, I did noticed lower condensor fins not pristine)
2. I have determined that if I juice the idle while stopped increasing fan voltage, causes AC temp to fall into normal range more or less. It appears I have a voltage signal problem somewhere ? Any suggestions.

Thanks,
ed

Resolution:
Installed new compressor, charged system correctly-using charging cylinder correctly !!! My understanding is that charging must be within +/- 2 oz of required weight for optimum cooling, always allowing for the ~2 oz of freon loss contained in charging hoses and manifold.
It seems that I originally did not use "charging cylinder" correctly and ended up "slugging" the compressor damaging compressor thereby diminishing compressors performance. "Slugging" the compressor is done by introducing liquid into suction (low pressure) port. With damaged comp A/C cooling was adequate when flow across the condenser i.e. while driving but not cooling when at idle or stopped in traffic.
Charging cylinder is a charging device most DIY'rs will not have available and allows correct measured weight of freon to be introduced. It's use requires engine/compressor not to be running !!! It has a heating element that increases PSI within charging cylinder and thereby enabling flow/charging an exact measured weight of freon in liquid form taking ~3 to 4 minutes via high pressure port.
Somewhere on the forum it was reported that since the suction port (low pressure) is directly on compressor of the S model the compressor is subject to damage (liquid slugging) and therefore should always be charged as a gas and not liquid. Unless, operator is FAMILIAR with charging via liquid with engine off, vapor/gas is always required as reported via numerous members commentary. A/C now is cycling between 33 and 37 deg @ 85/90 deg heat load.
Thanks to all forum members who aided in the resolution of my diminished A/C operation.
I have achieved a great education from your many comments and suggestions !!!

 

Sounds like a classic case of a bad DCCV.

 

Could be low on refrigerant.
Did you replace the compressor or are you asking if it might necessary?????

A/C gauges can verify if the internal valve is bypassing.

The TSB might help diagnose.

bob gauff

 

Thanks Bob,
Yes I have replaced A/C, dryer, used gages to properly charge system. Do you off hand recall proper charge values & pressures ? ( I am always compiling data use full for future wrenching). I will try and glean info regarding DCCV operation and it's possible affect regarding my symptoms.
Thanks,
Ed

 

I would reach down and pinch off the coolant supply to the DCCV with hose clamp pliers.

That will verify the valve operation (or lack thereof).

If the A/C cools properly, then you have your answer.

bob gauff

 

Wow,
thanks bob.

 

Bob,
I pinched off single coolant hose to DCCV from plastic bridge and did not affect AC performance. Re: poss low freon, I used gages and a charging cylinder to charge system when I replaced compressor. I don't recall R134 amounts or pressure in front of me but I vaguely recall 28 oz.
From my past wrenching with AC it seems that my symptoms are supposed to be related to lack off airflow across condenser ? I am still learning about the DCCV.
Thanks,
ED

 

What were the readings on the A/C gauges when the system was charged and operating??????

I usually get about 35 to 45 on the low side and 200 to 250 on the high side here in Texas in the summer.

If the high side climbs to over 300 then I start looking for reasons.

An old trick to find out if the condenser airflow is blocked is to spray water into the front grill and watch the gauges. The high side with FALL rapidly when the water carries the heat away.

You might try cleaning the radiator/condenser of accumulated debris.

bob gauff

 

Thanks Bob,
I will revisit the the high side pressures and water test, also will clean front rad & condenser.
Your time and helpful insights are greatly appreciated.
Ed
Santa Clarita, Ca

 

Dear Ed,

This older thread may be of some use to you:

https://www.jaguarforums.com/forum/s...ad.php?t=38751

In that case, the compressor performance was degraded enough so the computer never saw the pressure value that was the trigger to run the fan. I'm no AC expert, but think a low refrigerant charge could also affect the pressure readings enough so the fan is not commanded on when it should be.

If the fan is running, you can check for airflow blockage with the newspaper* test. When the fan is running, hold a sheet of newspaper in front of the grill. The airflow should suck the newspaper tight against the grill. If not, something is restricting the airflow, such as crud in the condenser fins.

FWIW, I can't ever remember hearing my '02 S-Type's fan kick on, even stopped in 100 degree heat (AC still blowing nice and cold). Not sure if the fan is just super quiet, there's great soundproofing, or it's just rarely needed. On other vehicles I've owned, there's no mistaking when the fan kicks on because it suddenly sounds like I'm riding a hovercraft.

*Newspaper: a pre-Internet device for disemminating the news, with words printed on actual paper.

 

OP, suggest you read known issue with original a/c compressor here: https://www.jaguarforums.com/forum/s...ds-help-58662/

See Brutals explanation on post 5 in the link I attached.

 

Thanks KR,
Your info as well as others has been helpful. I am no ac expert, but I have several successful ac jobs under my belt. One on my 928 porsche conversion to r134 and a friends 911 porsche conversion.
However, as you know the learning curve and all the variables can be a bit daunting.
To make a long story short I am working on my wife's 2001 S Type 3.0
I am tracking (1) on possible replacement compressor failure due to installer (me) error where I my have slugged the compressor using a charging cylinder to charge via suction port while running the compressor. I checked the pressures today and the low/suction are way too high (as per MOTORCARMAN commentary) 80psi and the high side too low @ 150 psi. When I increase idle to 2000rpm, low side come down to 45 ~ psi @85+Deg F. (2) overcharge condition which I will address tomorrow.
Keep my fingers crossed that I don't need another new compressor! It seems that my symptoms could point to compressor unable to deliver the goods at idle or stopped...NEW COMPRESSOR ?!
ed

 

Ed,
Where you able to solve you a/c issue.I have a 2005 S TYPE with the same issue.Please let know if you had any luck.
Thanks

 

Ed,
Your unusual pressure readings are indicative of the compressor valve spring needing to be serviced per the link I provided. TSB was issued by Jaguar to correct this issue. This will improve your cooling at idle and the unusual pressure readings.

 

You can mess around with the spring but you have a 2001 car and a new compressor is not very expensive. Get the Lincoln LS one for less money.

The newer compressors have eliminated the spring completely.
.
.
.

 

Tony,
The compressor in now I recently replaced because original comp was leaking at the shaft. Since this is a new replacement comp I don't think the valve spring would be the issue. I believe that I may have "slugged" or damaged the comp when I incorrectly charged the system. I am using a charging cylinder with instructions a bit confusing, indicating to charge via suction port with liquid watching psi careful to not exceed psi limits of low side. My mistake was that engine is suppose to NOT be running and should introduce r134 gradually so as to
not slug the comp with liquid. I incorrectly had my engine running with comp engaged as I charged system. The charging cylinder has 2 ports one on top (I think vapor) and the other on the bottom (I think liquid). Instructions for use a bit ambiguous. Instructions indicate to use bottom port of cylinder into low side suction.
Expensive learning experience. I guess I was just lucky on previous 2 AC jobs with same technique. One factor, the Jag S 3.0 has suction port directly on compressor, other jobs suction port separated via A/C hoses.

 

When charging the AC system the engine is supposed to be running - at normal operating temperature, AC system on, high fan at lowest temperature setting.

Your issue (as previously mentioned) sounds like the spring inside the compressor. Easy check - pull the back cover off (2 bolts) if the first thing that comes out of the cover is the spring - your fine - if you see that round metal gizmo (sorry - haven't had my coffee yet...) pop out - perform the spring switch.

Pressures - low should be between 35 - 45 PSI (when charging w/ R134a - reading will be higher) high side should range between 220 - 270 psi

Above pressures are relative to ambient temperature...

 

KR,
Please see "resolution" under original post. Thanks for your commentary, along with others, helped me in resolving my AC issues.
Ed