G'day, and Happy New Year.
This is going to entail a bit of history. In December 2019, I purchased my 2001 3.0 X type..a nice car with good service history. Being an old retired chap, it gave me something to do in lockdown,,,and boy, do we know lockdown in this part of the world.
About mid year, I had the aircon compressor and accumulator replaced. As the weather warmed, I realised that the aircon wasn't really doing it's job so I took it back...the response was that it had leaked refrigerant...it was refilled, and I was told that they couldn't find the leak...it was probably the evaporator.
After a couple of months of being underwhelmed by the aircon...now getting into summer, I took it for a second opinion, and was told it was full. He cleared some ECM faults, and told me that there was an issue with the cooling fan module. After some time at home, I found that the right hand fan was not running at full speed at all, so I wired it through the ignition circut (not ideal but at least it does the job...I couldn't keep my hand on that side of the condenser it was so hot)
So we come to now, 18 months on. Through the posts here I have been experimenting. I had the system emptied. I have purchased my own manifold gauges, vac pump, etc. and I filled the system with Hychill30..a hydrocarbon refrigerant that I can legally do. The aircon was no better. I then found the post (about a week ago) regarding reversing the spring and relief valve in the compressor. I did this, expecing great results, but only extreme disappointment resulted.
Now I have a system which is fully charged with refrigerant but acts like it is low.
The pipe on the evaporator side of the orifice tube gets cold and frosty, at high engine revs, but warms again at low revs/idle.
Since the aircon system is not rocket science, and the compressor is running, I have a couple of questions.
I have read all the posts I can find, watched countless Youtube videos, can anyone make any other suggestions?
Also, does anyone living in this part of the planet..around Melbourne, Victoria, know of some expert that I can take the car to?
It's a 36deg C day today..I need aircon!!
Sorry about the long post guys.

 

First have you checked the relays

 

Thanks for your response Dennis.
What relays are we talking about? If you mean the stepper motors and doors, they are all working properly.
I just figured that since the compressor was working, there are only 4 more items in the closed loop. So high pressure to condenser, high pressure liquid to orifice tube, low pressure gas through evaporator, return (sucked) back to compressor via the accumulator...so which of these items is not doing it's job properly. I started the car yesterday afternoon..it had been sitting in the shed...36°C day. The aircon cooled the air at the vent by about 10°, running at about 3000rpm.

 

Have you tried sending the airflow to other vent outlets via the heater controls?
Our heater systems can have actuator issues that due to a mechanical shaft registration issue can misdirect airflow....so before you start chasing Zebras make sure it is not misdirection rather than ineffective AC coolant flow.
Also.....it us curious that you need higher RPM to get AC somewhat effective.....are you seeing the compressor clutch dropping out when you are at lower RPMs?
Any difference in operation when your switch to manual AC on and minimum temp settings so it is not in any auto operation and not trying to reference cabin temp sensor?

 

If you can get a Jaguar enabled fault code scanner, there are about 20 or so Bxxxx type codes for the climate control system that won't trigger any warning lights or messages! The answer could be in there.

You've had the refrigerant circuit open and empty; did you put the system under a prolonged period of vacuum to ensure all the inevitable moisture was removed before filling it? If not the fixed orifice or the integral strainer could be partially or completely blocking with ice.

Is the external temperature sensor reading correctly?

Extract from the Jaguar Training Document

Refrigerant Flow Control
The refrigerant is metered by sending the evaporator sensor signal to the climate control module and then on to the
engine management system (EMS). This signal allows the engine management control module (ECM) to cycle the
compressor clutch in and out as dictated by the evaporator temperature. The overall effect is control of refrigerant
flow through the evaporator.

 

Thanks Astromorg and H202steam.
I see what you are saying but I think the problem is still in the refrigerant loop.
From starting the car, aircon on cold, running at 2000rpm, the compressor runs for about 5 minutes without shutting off.
The HP pipe, from the fixed orifice to the firewall is cold....frosty even. ( I even removed stepper motor #4 to make sure the mixing door was at full cold position...getting really good at removing that thing.) The air , and it will come out of any vent set, so the face vent is cold on the right side but could be colder, and warmer on the left side.
My research says that this is symptomatic of a low refrigerant level, but I know I have a full charge.
Oh, and by the way, I evacuated the system for about 90 minutes prior to recharging.
Now, when the compressor starts again, it runs, but the pipe from the orifice tube to the firewall is not very cold, in fact I'd say it's just cool.
I hate being beaten, but I think it's time to track down someone who is familiar with the jag....my last two guys that worked on it haven't managed to fix it.
I'll hunt someone down next week..I hope...most places are on a new Year break and/or short staffed with Covid issues.
Thanks again for your repsonses

 

Without knowing what system pressures you're getting at different times, it's difficult to be sure of anything, but my feeling is that you've got a leak somewhere and thus you're undercharged. This article might be an indicator to some of the problems Hychill 30 can suffer from

https://owenduffy.net/blog/?p=15593

Or the compressor might just be worn out!

 

Thanks again for your response. It had the compressor and accumulator replaced and system gased about mid 2020 (I purchased the car in Dec2019 as a Sunday drive!)
I did thid as the compressor was leaking lubricant onto the shed floor.
I haven't got confidence on the guy that did the job, and the person that had a look later that year said the system was full.
I'm leaning towards a dud compressor but will take it to someone that specialises in Jags for another opinion
I read the Hychill info..thanks for the link. It doesn't appear to have leaked since I filled it.

 

G'day all.
I've been a little slack in getting back to my Aircon problem.
However, after feeling like a dog chasing it's tail, I decided to take it to a Jag specialist.
This was after a lot of experimenting of different refrigerant levels etc, but the system continued to have an extremely low pressure on the vacuum side, a fairly normal pressure on the high pressure side, so my thought was that it had something to do with the orifice tube, as the pipe on the low side of the tube was getting frosty, but still not making the evaporator cold.
Now the results, in case this is information that may be of use.
My jag man said straight away it sounded like a blocked orifice tube. If fact he said that before even seeing the car. Anyway, "tube" replaced, regased and the aircon/climate control works like a charm. He told me that the compressor type used has (I think he said) has carbon impellors, which degrade over time as the compressor ages which goes through the system and clogs the orifice tube. The orifice tube was most likely blocked when I had the first lot of work done...new compressor/Accumulator.
Cheers
Adrian