Hey Lads,

I am troubleshooting an air con problem on the XJ6 and wanted to get some advice or pointed in the right direction.

So it started with the cars AC running perfectly. Nice and cold and no issues. My wife one day said that the AC had changed. It was warm on the passenger side and cold but less cold on the drivers side then it had been.

My first instinct was that the car was losing freon and was compensating like I had seen on my BMW.

So I pulled the caps on the schrader valves and was testing for leaks as that is the most common area of losing it. While the car was running with the AC on, the high side service valve vented all the freon and I could see and hear it vent out. So I thought problem solved and as usual it was the schrader valves.

After some purchasing research, I opted to buy a new pair of hoses from URO with a regular schrader valve for future service consideration. Replaced both hoses to and from the compressor and had the system recharged this morning. Everything is tight and the system functions.

However,
I still have the same condition that my wife complained about. The drivers left vent is the coldest at below 55F and then the vents get warmer as you go to the right. The drivers right is a usable temp but only around 62F. I didn't measure the passenger side ones. They are just plain warm.

I checked the solenoid switch in the engine compartment and it is good. Warm on one side and cold on both output hoses.

So in your infinite wisdom, where would you go to look for the problem? Is it door related, motor related, or something else causing this to happen?

Cheers
Bernie

 

Hi Bernie,

I also have a BMW that had those same symptoms and was cured by recharging the freon. Since that hasn't worked on your Jag, one thing that comes to mind is the heater water valve - perhaps it is stuck open and always allowing hot engine coolant to circulate through the heater core, diminishing the performance of the A/C.

Here's some additional info that might have some clues:

X300 Climate Control System Self-Test Procedure:

JagFORUM Logon


Jag-Lovers X300 Ebook:

Jag-lovers' Ebooks Book Index


Hopefully you'll hear from someone who has had the same problem on an X300 and resolved it.

Cheers,

Don

 

Ok, thanks.

I need to sign up to that site to view the documents and I will do that.

I have noticed that when the recirculation button is not illuminated, the air feels cooler than when it is. I assume that light on means it is recirculating the inside air? That's strange as it is 95F out there today.

The other strange thing is that all the hoses to and from the compressor are hot. None of them are cold even though I am definitely feeling cool air coming out those vents.

I have also seen that it could be a flap or flap motor problem and it could also be the AC module itself. The valve you mention is the one at the firewall on the drivers side above the coolant pump correct? US version of course

I checked the hose running into that and that hose was hot. The hoses on the output side were both cold so I think that it is working properly.

Hmmmmmm

 

One of the problems we've seen is the dessicant bag in the receiver/drier lets go and fouls the TXV with beads.


When you got cooler air by turning off recirc...was it after a hot-soak and the car was potentially hotter than the 95 outside?
Not sure about the duct-paths to each vent, but IIRC, the evap core is on the driver's side so if your system is under-performing you may notice a temperature gradient as you check each vent that is further from the little bit of cold you have going on at the evaporator core. It is likely there all the time but one doesn't really notice the difference between 41 and 42 the way one does the difference between 55 and 62 when it is 95 out....


A suction line not cold to the touch is not a good sign.


Another thing, as long as you are messing with the air-conditioning, although not likely related to your problem, go give your condenser a good shake and make sure you still have the upper and lower isolator mounts installed. They tend to depart during use and if undetected, you will eventually wear a hole in the condenser tube.

 

Thanks for this info.
I had already replaced all the bushings for both the condenser and the radiator so that shouldn't be an issue. Plus the shop pulled down good vacuum on the system prior to refilling so its somewhere else.

Maybe its a larger problem but not being an AC expert, I have only a few ideas as to where to look. It certainly seems to me that the temps go up and down randomly too. The climate computer can be had off ebay for like 20.00 so I may elect to just try that first as in the grand scheme of the system, it is pretty simple compared to some of the other checks.

I will keep looking in the meantime for any posts of similar symptoms that would maybe point towards a common failure.

Thanks!

 

So before going any further with the AC, I decided to head back to the shop and have it rechecked.

Turns out that he only put 2lbs of R134a in it the first time so that needed to be increased but that wasn't the real issue. For some reason the car was extremely slow to accept the freon?

He had to put in a little at a time and it took about an hour to get 40 oz. in the system. So now the vent is 53F with car at idle so I am happy.

I cleared the codes in the HVAC but code 12 came straight back for the interior ambient sensor. Which one is that? Is that the one on the panel below the steering wheel?

Thanks
Bernie

 

Bernie, I hate to tell you this but you need to find a new " shop". The car takes 2lbs 7 oz as directed on the placard and easy to find online sources plus it shouldn't be reluctant to take the charge. Serviced to 2 lbs the system should have been functioning pretty good. An hour????? That's A problem that I wouldn't just shrug off. A system vacuumed down will have no problem pulling in the R134 and servicing up in minuets. I'd like to see the pressures they were and are reading on both sides.