Hey Lads,

As much as I wanted it to be true, I have not successfully cured the problem with my AC.

Just picked up the car today from the shop after having the compressor replaced. It was a rebuilt and the shop said that they tested the original compressor and it was indeed bad so that's good right?.....lol

Well the vents on the driver side of the dash are blowing cool air but not cold and the passenger side vents are blowing hot air.

I also checked the high and low pressure lines in the engine bay which I had replaced before and both lines were hot. I don't understand this as there is definitely cool air coming from the drive side but not cold.

Been doing a little research on the board and there is a lot of talk about the expansion valve going south so I am wondering if that might be the issue in the end? Doesn't explain why I still get some cool air on one side of the cabin though or does it?

I think the low pressure line being hot is a good clue but I am clueless as to where to go from here? I have no issues tearing the dash out to replace the part but I don't want to throw any more money and effort at it unless I can absolutely confirm that it is indeed the problem so how do I do that?

Cheers
Bernie


UPDATE:

Ok, so I decided today was as good a day as any to finally buy myself a set of gauges for the AC systems that I seem to work on more than I would like.
Remembering that the car had just been brought back from the shop after getting the compressor replaced, I checked the pressure in the system.
The AC gauge manual stated that typically the lowside of the AC system should be about 45-50 PSI and the high-side at 110 degrees F, which it was here today in Las Vegas would be around 345-350 PSI.
So when I checked with the gauges, my low side was at only 20 PSI and my high side was at only 275 PSI. I figured that either the system was losing freon quickly or that the shop for some reason did not put enough R134a into the system.

I went to the local shop and picked up a 12oz can of 134a and proceeded to fill the system with it. Watching my lowside gauge, I got up to about 35 PSI and the system wouldn't take anymore than that so I stopped. When I hooked did a pressure check again, my low side was of course at 35PSI BUT my high side had shot to nearly 400 PSI!! This alarmed the **** out of me but the system in the car was cold from all front vents. I bled some of the freon out to around 30 / 365 and hoped that the system could handle a bit more pressure than suggested.

So, am I right in thinking that the expansion valve may indeed be the problem here?
I was still 15PSI away from the upper limit according to the manual and still the high pressure side was going off the chart.

I am absolutely no expert in AC systems but I did learn a lot today. Not looking forward to hauling that dash apart so I am trying to get any advice I can to make sure that if I do go in, it will fix the problem.

 

What I would do in your position.

Download this manual:
http://ecat.spectrapremium.com/bulletins/download/automotive_techtip_eng_2007.pdf

Buy a LED UV flashlight on ebay. In complete darkness, shine the light all over the a/c components. Leaks will be evident by glowing brightly.

Fix any leaks.

Replace receiver/dryer.

Buy or rent a vacuum pump and evacuate the system.

Find out the capacity of the system.

Watch a few Youtube tutorials on re-gassing do's and don'ts

Put exactly the recommended amount of gas in there. Too much probably worse than too little long-term.

good luck!

Larry

 

If UV dye was used when it was recharged...

 

When was the last time you ran across a system without dye in it?

Anyway, if no dye (unlikely in an old car), get a 4 oz aerosol can from autozone and fire one ounce in.

Larry

 

But, in answer to your original question, if your original compressor really was bad, depending on the failure mode, it is likely that it contaminated the system. If they did not install a filter and/ or fully flush the lines (which is pretty hard to do), then YES, the expansion valve might be plugged.

I gotta ask... If you just picked up the car and it is not cooling, why are you troubleshooting it instead of the shop?

 

The shop I bring the car to basically helps out.
They don't charge me a lot to work on my cars and we have a sort of understanding that I do most of my own work and they do what I ask of them.

The cars AC is currently cooling just not what it used to be so there is something else going on. I also have a New Beetle that has a completely dead AC system so I have been purchasing the tools and watching the videos on how to troubleshoot and do this kind of work myself. I have a few more pieces to pick up and I will be able to do most any AC job and I also picked up new parts for the Beetle to fix its AC system.

I am pretty confident that its a expansion valve / evaporator problem at this point. So the dash needs to be removed to get to the problem which I am not going to tackle in 105F temps. Interior of cars in Vegas can hit 140+ degrees when the windows are up!

I will let you know what I find once I have completed the work. As it sits, the AC works well enough to keep things under control.

Thanks to all of you for the informative replies.

 

Razorboy,
do you have any error codes showing on your heater panel?
With the ignition turned off, press and hold both the recirc and auto buttons, and turn the ignition on. Release the buttons, and press auto to read off any error codes. JTIS has all of the codes, (23 is low A/C refrigerant pressure, i.e. a leak) and tells you how to test the operation of the various flaps in the heating system. From your original description of the problem, I am wondering whether there might be a problem with them. As well as controlling distribution to the various vents, they also control the temperature mix between the heater matrix and the evaporator. In other words, your A/C might be working, but the cold air can't get to the vents.
I hope this helps.

 

I do not.
There used to be codes on it but I found and fixed those issues and have not had one since. I will certainly check to make sure all blend doors are operating properly but here is the thing,
When I got the car back from the replacement of the compressor and the charge, the passenger side vent was blowing noticeably warmer air than the driver side.
I bought the gauges and at the time, the low side was pretty low (20-25psi) and the high side was low too. So I though maybe they didn't add enough refrigerant to the system? I bought one can of 134 and after about a quarter can, the low side had come up to 35 psi but the high side had shot to 375! So I bled some of the 134 out of the system again until the high side came down to about 350.

So its a bit botched right now and I plan to go back and do it correctly BUT now the passenger side has much much cooler air and almost identical to the driver side.

 

The X300 doesn't have dual zone climate control, so I think the problem is in the blend doors or something internal to the the car, rather than the refrigerant charge.

There are 2 blower fans inside the car for the heat/AC, do both of them work?

 

Check the linkages to the flaps. If there are no error codes showing, it may be that the motors which control the flaps are fine, but a linkage has broken or come off.
If you are not showing code 23, you have enough pressure for the system to try to operate, and the fact that you seem to be producing cold air suggests that it is working, and that the problem lies in the distribution side. You mentioned resolving some heater panel error codes: maybe retracing your steps might provide some clues?

 

Razorboy check your blower flaps, they operate via the climate control module, if you need to flush the whole system, use high pressure nitrogen gas, it is easy and a walk in the park, follow discharge procedure and recovery of Freon gas, before you start flushing make sure to take out the dryer tube and check if the silica gel bag is still intact. The expansion valve rarely breaks, the only thing that can break the function of the valve is when dirt particle from within the system gets stuck in the valve.

 

So, I had a new compressor, condenser and evaporator put in. It is cold , however, the fan speed is off.

1.Start the car, temp set at 67 blows cold air but slowly
2.Turn temp up to 73 or above and it blows fast, the way it used to work.
neither scenario involves turning on recirculate. the lower you go the slower it blows. If you put it on LO it blows correctly. at 67 the air coming out is measured at about 36 or 37 farenheit.

What are we missing??

 

Dagny,
One logical interpretation of what you are saying is that the interior temperature is around 68. With 67 selected, the car would be trying to cool itself slightly, hence cooler air, but low fan speed. Select 73, and the car needs to heat itself by several degrees, and would select a higher fan speed in the first instance.
Selecting low removes temperature from the equation, and selects max cooling, max fan.
It is also worth noting that there is a noticeable delay sometimes between selecting a different temperature, and a reaction from the system (at least there is in my car, which generally seems to work ok, touch wood!)
Sorry if I have misunderstood your post.

 

I was somewhat unclear. The temperature yesterday was around 90 and the car was hot.

1.Selecting low removes temperature from the equation, and selects max cooling, max fan. Correct, I agree.
2.From 61-72, the higher fan speed does not engage at all.
3.At 73-90 it engages as it should (or like it used to)
4.The other variable I forgot to mention is that the external temperature sensor was replaced. I'm not sure if this provides an input into the system or not. Before it was replaced the pael for the AC would read ER when you pushed the EXT button. Now it shows ---F.

As always I appreciate all the feedback

 

Dagny, back in the mid-90's...when our cars were produced, albeit some years after they were designed...I had the opportunity to pick the brain of Ford's chief auotmatic climate control design engineer. So I can assure you that Ford's EATC definitely used the ambient air sensor out at the grille as an input to the climate control methodology. He further advised me that they used the sun-load sensor on the dash as additive to the ambient sensor input. The general philosophy was to use high-blower for rapid cooldown but start retarding blower speed as the vehicle approached set-point and keep it as low as possible and still maintain set-point. "People don't like to hear blower noise..." As you reduce blower speed, the air is in contact with the evaporator for longer, resulting in colder discharge air, so they would feather the temp flap to avoid the frozen-knuckles-syndrome. The set-points and ranges where they made these moves and the magnitude thereof is/was proprietary and thus not shared. However, I suspect the basic design objectives are generally common across the industry.

Sounds like you have a problem with the fan control but I have no idea what it is...if ambient was 90, 61-72 setpoint should've got you high blower unless the car was already cooled. Would the fan go to high in that temperature set range if you spun the blower switch? Manual control?

 

It turns out that the AC needed to be reset to factory configuration and everything is working now including the outside temp sensor. I neglected to ask where that module is, so if anyone is really interested I will go back and ask. I would guess it might be part of the main module though?

 

For some reason every shop looks up the amount of freon needed and puts just that amount in and stops. That is NOT ENOUGH. What you did and the pressures you wound up was right. STOP and enjoy it. It is working good. The expansion valve is working right. You did it right the shop did it wrong.

 

Following on from the above, I ran the test for error codes after my AC became somewhat ineffective. It showed codes 12, 23 and 24. So, given that code 23 suggests low pressure/leak any thoughts on what the other two codes might be? Any tips or advice on topping up the refrigerant? Recommended brands, quantity etc. And a "how to" would be good also!Thanks in advance.

 

According to JTIS,
12 is "ambient temperature sensor" "open/short circuit After rectification disconnect vehicle battery for 10 seconds to reset"
24 is "face vent demand potentiometer" "open/short circuit"
For the sake of completeness, code 23 can also be due to a faulty pressure switch as well as low gas pressure.
If you have just checked for codes once, it might be worth clearing the system and then seeing whether the codes return. They could be historic. press "face"and "HRW" simultaneously to clear each error.
If they all return,given the assortment of codes , it might be worth trying to retrace some of the cars history in particular to try to understand whether someone has been working on the climate control system before you. Could just be loose/ dirty connections in each case, although history would suggest you would be very lucky for that to be the outcome!
Hope this helps

 

I used Arctic Freeze R134A in my BMW a couple of months ago and it worked well. I bought the one with the gauge and no leak sealant. I think it was a 14oz can and I probably used about half from the weight of the can, took about 10 minutes. Just follow the directions and it is really easy if you only need to do a boost.
That said, nothing on the Jag is easy. I gave up and had the whole system on the Jaguar redone with new parts:
1.Compressor 545
2.Condensor 170
3.Evaporator 75
4.Ambient Temp Sensor 122
5.Labor and Freon was 625