On any other car I would gas it using the gauges looking at the system cycling.
With the clutch-less compressor you dont see that so I never bother with the gauges.

I make sure the system is evacuated connect the vac pump then fill by weight alone.
When filling I always add some die to be able to find leaks latter on.
Id also never fill without replacing the desiccant bag

Cheers
34by151

 

That's interesting diagnostic information. From my view, your pressures look fine but the vent temps are abysmal. That makes me suspect you have a blend door issue that is mixing heat back into the air stream instead of giving you full cold.

The 300 psi high side with R134a doesn't make me terribly alarmed (with a 97F ambient). The high pressure cuttoff will be somewhere closer to 375-400 psi.

It is possible you have a clogged TXV, but I don't see your low side pressures dropping excessively low. To rule out a blend door I'd use a hose clamp to shut off heater flow entirely. You will have to unplug the aux pump (or pull its fuse), and on one of the heater hoses use clamp pliers like this: https://store.snapon.com/Shut-offs-H...s-C675567.aspx

If closing off the heater coolant circuit restores your vent temps back to the 30-40 F range then you know it's a blend door issue. If not, then I'd start looking at TXV issues. (If this is confirmed, a quick fix without dismantling the dash would be to install an in-line coolant shutoff valve in the heater circuit).

Also, can you feel the inlet and outlet pipe to the evaporator? I'm not sure these are accessible in the cowl or behind the engine. That can tell you a lot about evaporator superheat. The inlet to the TXV should be hot (high pressure liquid side). I don't think you can access the outlet of the TXV because it's integral to the evap assembly. But the outlet of the evap should be accessible--if it is warm, then you are undercharged or the TXV is closed. If the outlet is icy cold, then it's working as designed.

 

When I had a similar issue, no or very little cold air at stop on a hot day, it slowly turned into overheating on really very hot days. Ended up being tired radiator fans and a gunked up original radiator on a car with 140k miles.

Invested some money into a new OEM radiator and fan and now it's as cool as can be whether stopped or not.

 

I apologize for taking so long to reply to this post. Yesterday during the heat of the day I parked the car on the hot parking lot in full sun with the hose clamps on, heater aux. pump fuse pulled out and maximum A/C turned on. I left the car for 30 minutes running. The issue with the hot air blowing did not go away. The air vent temperatures were slightly better, but still not cold air blowing out of the vents.

The search continues......

 

Hello NDW,
Wanted to follow up on your case. I'm curious to know if you found the culprit.

 

@BlackKat I am sorry to report to you that I have not found the culprit or a solution to the problem. Last night was especially uncomfortable in the car until at highway speeds for awhile.

 

Hello everyone,
I apologize for the delay in updates. As usual summer is the reminder of AC faults.
Previously I have replaced expansion valve, condenser, desiccant, compressor solenoid valve, then the whole compressor.
Last July I decided to go all the way. I pulled the dash out and took apart the ac housing to replace the evaporator core. While I was there I cleaned the housing and baffles. I removed all the old foam on baffles as they were crumbled off. I used a foam tape for campers on pickup trucks. It's a very sticky tape with very soft foam. Very confident it will not peel off the baffles. Believe me I had a hard time removing pieces from the work bench. See the pictures below.

Of course in Jaguar fashion I'm still in the same boat. I will admit things are slightly better but not new car cold better and definately no good at idle. But I'm already in too deep and figured why not go all the way.
Having replaced almost everything all that's left is the expensive radiator fan. Which I do believe has gotten lazy.
I have 3 options:
1 replace with OEM at $700 USD
2 buy used and rebuild brushes about $100-150
3 somehow install an aftermarket one

Let me know your thoughts.
Thanks in advance!

 

Hi BlackKat,

I commend you for all the hard work you've done and can relate to the pain of minimal improvement for all that time and effort.

Your refrigerant pressures look fine for Texas.

Off the top of my head, remaining issues that could contribute to your poor cooling could include:

Poor air flow through the condenser

Blend doors incorrectly positioned, perhaps due to stuck or miscalibrated actuator motors (the Workshop Manual
may have a calibration procedure or this may require SDD)

A problem with one or more of the sensors referenced by the CCM:
Evaporator Temp Sensor
LH Outlet Air Temp Sensor
RH Outlet Air Temp Sensor
Ambient Air Temp Sensor
Smog Sensor
In-car Temp Sensor
Humidity Sensor
Dual Solar Sensor
A/C Pressure Sensor

If you have a scan tool that can read Live Data, you may be able to view the output signals from some or all of these sensors.

Cheers,

Don

 

@BlackKat , all I can is WOW! on that first picture. You really did go all of the way on that one. I showed it to my wife, and her response was, "we're not doing that...." My hat is off to you for persistence and dedication.

Will be interested to hear about the new or rebuilt cooling fan outcome. Hope you find that new car cold air we are both searching for. For those that don't know, @BlackKat and I are in the same boat in the same warm climate.

 

Hello everyone,
I just ordered a used radiator fan from Ebay. I decided to go with the rebuild a used one route.
I will crack it open to inspect the brushes and try to locate new ones. Will keep guy guys posted; probably on a separate thread for ease of future research.
A side note; I strolled through the local hardware store and came across the Camper Tape I used to replace the baffling foam. See the pic below. I used 2 of these rolls.

 

Wow, that was definitely a lot of work and I'm sorry to hear it didn't solve your issue. Your pictures reminds me of the guys with Mercedes W126 pulling the entire dash to replace actuators on the hvac module...

I'm hoping a new fan will help your problem. I have to say, with a low side pressure near 50psi you probably don't have good cooling. Your low side is going to want to be in the 30-40psi range (depending on heat load and ambient). High side pressure is not terrible. What was the ambient during that reading? You said the compressor and condenser are also new?

I do agree with Don in checking the HVAC sensor readings as a sanity check. If the module thinks the car is already cold, or not sensing the correct solar load, it may be reducing compressor capacity (variable displacement).

 

Thanks MHamilton.
Reason I'm leaning towards radiator fan is that at idle the vent temp drops to 80F from 120-140F. This is when I start my car at then end of work and let it run for about 10 minutes while I change into gym clothes. Once I hit the highway the vent temp drops to 60F within a couple of minutes ultimately to 56F after a good while. Outside temps in the 90sF.

I pulled the temperature records for July 15th 2018, at 10:53am. (the gauges picture was taken at 10:51am) according to official record ambient temp was 91F and humidity at 56%.
According this pressure chart I should be in spec. At least I think according the chart below.

I'm currently having SDD troubles to check the sensor probe readings. Can't get SDD to communicate to any modules via CANBus, but haven't had time or patience to play with SDD much. (been busy with also replacing suspension components). The other option would be to take resistance reading of the temp probes but would require me to remove the dash again.
There are only 2 sensor probes at the center front vents and 1 cabin probe by the ignition key. There is no evaporator probe! At least not an electrical one. The only temperature sensor at the evaporator core is built into the Thermal Expansion Valve. There are no electrics to it to gain readings.

When I opened the AC Housing I did noticed that all the baffles were in the correct position for max cooling, front face vents open (which forces the defrost vents closed), all 4 evaporator baffles open(2 per side), heater baffles closed and floor baffles closed. In Jaguar fashion I wouldn't be surprised if all these move as soon as I turn the system on but would require SDD running to verify.

Nothing is ever easy with these Jags, you have to fix something first in order to fix something else.

 

I suppose that low side is in line with that ambient heat load. Did you ever try misting the condenser at idle and see if the pressure drop rapidly? Not a full water spray, just a mist (if you have a garden nozzle with that setting). If so, that would indicate poor airflow, as also confirmed by your experience having better cooling at speed.

I'm a bit concerned at the temps you say you're getting when it is "working" are only 60F-ish. I will find a thermometer and check my car when I get a chance. I've got the same ambient temps as you do here in NC, and at the end of the work day I start the car and the ac will be blowing air in the 50s in about 1 minute. It stays on recirc for about 10 minutes in stop/go traffic, and then after that I'm freezing. I have to bump the interior temp to 73/74F.

 

Thank you MHamilton that will be very useful! If you could also please record the humidity. I've been thinking about gathering vent temp data from different users at different temps and humidities to build a table specific to X350.

 

Today wasn't as hot as expected... it was "only" 94F with 35% humidity so it wasn't a severe test of the system. Video link below. Car was parked in partial shade, started up and idled for a minute, the center vent temps were in the 50s. Clock in dash is a handy time stamp. Drove at 35 mph for < 1 mile and was in the 40F vent temp. By the time I got off the highway temp was near 30F out the center vent, I had to put the interior temp to 74.

BTW, my a/c system performance has been exceptional this summer because I replaced the condenser/dryer assembly in the spring after a leak at the service port left my system bone dry during the winter (used a Behr condenser, available on RockAuto and FCP Euro). The old one had the bottom 1/3 smashed by road debris over the years. I figured I must have lost about 25% cooling capacity. Evacuated the system and charged by weight to spec. Been the coldest a/c I've ever experienced with this car.

Did you get a chance to try misting your condenser and observe pressures? Stupid question, but you did pull a vacuum before charging the system?


Here is 2 minutes after startup, waiting at left turn light:


Here is 15 minutes later, drove 10 miles on highway and stopped at offramp:

 

Thanks a bunch MHamilton! Didn't get to spray the condenser yet, the rain we got Saturday evening ended my day early in the garage. I spent Sunday having to do my girlfriends brakes, plugs and coils.
At the previous refill I did pull a vacuum for an hour and held it without any leaks. I measured the refrigerant by weight using a dedicated refrigerant scale. (My brother is an appliance repair man got to use his refrigerant tools and expertise on the equipment)
Wow looks like your AC is running strong! Loving the data, very helpful.

 

Hi BlackKat, I just re-read this entire thread. I didn't realize both you and NWD were having the same issues. Now I'm less confused

It's hard to say via remote diagnosis, but my intuition is telling me there's something wrong with your basic refrigeration cycle. The low side at 50psi is never going to give you cold air. You said you replaced the TXV and compressor--were there any signs of contamination in the system? It does not take much to clog a TXV, and the new valve may have clogged as soon as it was run.

When the ambient temp is lower than 90F, or there's no solar load, does the AC work and blow very cold air? Or is it also suffering in the 50-60F vent temps and not dehumidifying the air?

I think in addition to low/high side pressures you need to measure superheat of the evap. This simply means measuring the temperature at the inlet and outlet pipes of the evaporator with contact thermocouples. Having the variable displacement compressor adds another variables to the mix, and that doesn't help anything.

 

Last week when the weather was hot in the UK (35 degrees) and crawling up the motorway in traffic the air conditioning became warm followed by the temperature of the engine creeping up. I ended up pulling onto the hard shoulder (couldn't hear the fan blowing). I did the old trick of putting on the heater and the engine temp dropped like a stone. Once it had dropped I started the engine and drove home (not much traffic so no problems and air con ice cold). The following day (another hot day), I started the car and drove out and could hear the engine fan running (air con ice cold) after 20mins I drove home, once home engine fan not running and air con warm again. Temp crept up. Switched car off and on again, fan came on at full speed to cool engine down. It has been at a garage for a week and they cannot find anything. Any thoughts?

 

Hi Jinkster,

Welcome to the Jaguar Forums! It's great to have you with us.

You can help us help you by telling us the year, model and engine of your Jaguar. Different models have different fan management systems. Try using your User Control Panel to edit your signature so these details appear in all of your posts.

Also, please visit the New Member Area - Intro a MUST and post a required introduction so we can learn something about you and your Jaguar and give you a proper welcome.

Cheers,

Don