I picked upt he car today. I thought the air conditioning tested ok when I purchased the car. I was wrong. I crawled under it and hooked up a gauge to the low side and had about 50psi (about right) when it was running. The suction side is hot (not cold) and the discharge side is burning hot .... Hmmm.... Something is very "not right". Suction side should be cold!

has anyone been down this road before ....

seeya
Shane L.

 

No, not been down THAT road exactly before, but:
It sounds serious.
I had other AC issues before: 1. Seized compressor, 2. Old leaking seals.

Ah, I see you are in my neighbourhood (i.e. Australia). Thinking that you are in the US, I just wanted to ask you not to simply try to add some R134a into the system. but to investigate the issue properly. But you do not have that option anyway: Every Tom, Dick and Harry can but R134a dirt-cheap in the US, but the sale of that is illegal to the general public in Australia...

Thus: If your A/C does not work anyway, I recommend as first step to drive to an AC specialist to firstly confirmed that you have refrigerant missing, and if so, have the remaining refrigerant professionally and environmentally safe sucked out. Simply releasing that refrigerant into the air is a crime against nature and us all.
Obviously, while you are in the AC shop, ask them for advise. But if you were low on R134a, I'd recommend (if you want to do that yourself) to swap out all the seals (you get a big box with all kinds of different sizes of those green AC seals from various cheap online sellers), and when you are done, go back to the AC shop and have - that is normal anyway - ...have a vacuum test done to start with (which you could obviously also have done there before swapping the seal, if you want)...

Also: Are you sure your compressor is working properly - there are also seals inside of the compressor - and without R134a, the system cannot work...

And while you are

 

Are you getting any cooling? Try working through the troubleshooting guide:

https://www.jaguarforums.com/forum/s...ol-how-185002/


Please be aware some aspects of the AC system are quite different than other vehicles. For example, the compressor has a self-regulating feature that can trip you up while troubleshooting if not familiar with it.

 

Need to post hi and low pressure and start from there. Follow what Karl posted above.
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Fantastic, I'm off to have a read. I'm not going crazy. My youngest wanted to go for a drive in it, so I took him to school in it .... and its certainly working when there isn't much heat load. You can hear the refrigerant hissing through the dash. It just falls in a heap when it warms up though (its 35 -> 45 degrees across Australia at the moment).

Air-con specialist? I guess you guys don't know me yet, I'm the biggest tight **** you will find.... and I enjoy trying to figure stuff out for myself. My manifold and gauge set has seen better days, the high side connector is broken up. I'll order in some new gauges and read the links and try and figure out what is going on. I had to laugh at how long it took me to find the low side service port (that didn't half make me feel stupid .... or should I say frustrated ... why hide the thing .... Don't worry, I own french cars ... the french love hiding stuff too).

I have vac pumps and A/C gear here that I use on my other cars. I just use BANG!!! gas ( Hychill HR12, its a propane/butane mix, that is as efficient as R12). Its great in the old cars I own. It doesn't matter if they weep a little refrigerant away from there 40+ year old lines and A/C components. It's little effort to top them up ever year or two if you use them in hot weather.

The S type seems leak free though, I'm guessing the compressor is junk, I'll read through all the how toos first before I come to a final conclusion

seeya
Shane L.

 

I am with you on AC work. The cost of shops is just over the top. So I also do all my AC work. Just read and understand the system your working on. As Karl mentioned there are a few things that are a bit different. I find the cost of gauges and the vacuum pump to be paid for with 1 or maybe 2 AC repairs.

I think your smart to consider a compressor replacement after all these years and miles. With your other comment you really need to get the repair manuals if you plan to DIY things. JEPC and JTIS are the factory versions and are the best out there but they are old and obsolete now. Both are free and on this forum but will take a bit of DIY to find and install.

We have massive threads on both of these if your interested?
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Like you say a high side reading will help a lot. Is your cooling fan coming on with a/c on. If you have an infrared thermo shoot the condensor as best you can

 

I'll get to it, I'm just waiting on the new gauges to arrive. Interestingly the A/C seemed to be working this morning (when it was cooler) as I moved the car in/out of the shed. I'm wondering if just doing the fix to the compressor (reversing the spring) might bring the A/C system back to life (as suggested in the link above).

 

So I read that overview at the top of that thread a few times. Now I'm great at taking advice .... So went staight to the end of the document and found the link to the compressor details and found the "modification" to the compressor. So yes, I went through all of the steps as instructed ... my brain didn't immediately go ... "look car over there to play with" Well when I got the car home after bloody near dying in the heat, I did grab every heater line into the cabin I could find (there seemed to be multiples of the damn things), anyway, they were all warm to the touch after driving for 1.5 hours in the 30+ degree heat. Which means, no hot water into the car (they should have been burning hot). Also I would have died in the damn car if the heater was on (trust me, I know HOT cars, I've owned Citroen CX's since I was 16years old ... the hottest car to travel in known to man).

So I er, hooked up my refrigerant recovery system and removed the refrigerant. Access is limited but way better than I'm used to, so I whipped the plate off and reversed the valve. Then vac'd her down for about an hour (its humid here). I didn't change the drier or anything, as I'm just trying to verify the thing will work. No point changing that until I know I don't need any other A/C parts (eg: compressor .... TX, etc).

Anyway, I dump 320grams of BANG!! gas into it.



See, I can follow instructions I found the cheapest, crappiest temp tester I could at the local hardware store. You know, its pretty crappy and inaccurate.



But it is about 30degrees C in the shed.


No heat soak yet. I imagine that will dramatically increase if I drive the car. I can hear the condenser fan running.



Hmm... I might have got incredibly lucky here. I'll use the car for a couple of weeks and see if the A/C is infact working (I put a temperature probe in the vent, it reckoned 10degrees, but its also the cheapest bit of junk I could find). That is still a 20degree C drop across the evaporator.

Fingers crossed I've had a win here

I haven't checked the heater yet, that is a problem for "later on" when the boss women needs a heater, fingers crossed that thing just works! Otherwise I might have to read that amazing diagnostic page again

 

BTW: Don't drop the service port caps. I dropped the high side one down into the engine bay .... couldn't find the damn thing. So I tried other caps on there and none fit What in the hell, so I googled it and they appear to be a non-standard cap. You do need the cap, as they are an "O"ring cap that seals the system. You are not supposed to rely on the schrader valve. Anyway, fortuantly (after several attempts) i did find the cap, it was sitting on a housing that protrudes out the front of the motor under the pulleys. Phew! What a crazy problem to have over a small plastic cap!

 

Good to hear you are making some progress. But definitely check the heater operation. The DCCV is a known problem. It is very common for one or both sides to not shut off completely when commanded.

The end result is unwanted heat dumped into the cabin. You can have the AC side of the system in perfect working order, cranking out frosty air suitable for penguin smuggling. Meanwhile, a suspect DCCV is dumping heat into the same ducts, making you wonder what’s wrong with the AC.

The troubleshooting guide has one check the DCCV first for just this reason. You didn’t take the troubleshooter’s oath, did you? Went straight to the technique where you run around like a chicken with its head cut off?

 

Yep, I will go through it at some point. I'll probably check that heater valve soon'ish as the water pump is weeping around its gasket, so I'll need to drain/change the coolant and replace the pumps gasket. Unless its possible for both valves/solenoids to get stuck closed (so no heat ever) I'm guessing its ok. Its 6:00pm at night, bright and sunny ( 34 degrees C in the shade) and both the vents are blowing lovely cold, refrigerated air when I just took it for a test drive. This is with the climate control just set to 20degrees. I think your right about the sunshine sensor, the air felt to get colder (weird) as I backed it out of the shed in to the sun. I figured it should already be fully cold as it would go (so its probably in my head).

seeya
Shane L.

 

It was a bit chilly this morning ... a mere 20degrees.... Yet the air felt cold/ambient in the car. Just for interests sake, I cranked the control upto "high" .... so should be full heat. Only we still get only ambient air from both sides of the dash .... Hmmmm..... something to fix before winter. I'd assumed that heater valve would die on "full hot" not "full cold" Given I've found a weeping water pump, what is the chance the level in the header tank looks right ... but we have a big air bubble in the heater circuit.

Should I go read that guide properly .... or just jump to the section that says "heater"

What does surprise me is the air conditioner, its not just working, its very, very good. Infact probably the best air conditioning in any car we have ever owned. Its so cold you end up pointing the vents away from you (even when its 34'ish degrees out in the direct sun). I know the guys in the USA will understand the 30->40 degree heat ( its been 90 -> 115 across australia over the last few week, if you listen to the nutters on the news its "record breaking" ... or its "getting hotter", its "global warming" ... Do you want to know the real truth, its "summer", we have hot summers and cold summers .... its is "normal", you can ignore the hysteria you see and read).

seeya
Shane L.

 

In theory, yes, the DCCV should default to maximum heat output if it falls. Both valves are spring-loaded to the open position for maximum coolant flow. But that's only if the valves are free to move. I had a seal swell up, reducing coolant flow on one side as detailed here:

https://www.jaguarforums.com/forum/s...repair-251854/

Others have had the DCCV jam in various positions due to debris, likewise defeating the spring-loaded action.

As far as air in the system, it's possible the coolant leak is affecting coolant flow through the heater core. The routing of the cooling system is fairly complex. I've noticed at idle the heater performance drops a little bit. Soon as I rev the engine, the heater output returns to normal. So it may seem counterproductive, but fix the water pump to get the cooling system liquid tight before condemning the DCCV.

After any cooling system repairs, these cars have an annoyingly complex bleeding procedure. The system is self-bleeding, but it is a slow process requiring several drive cycles (with a full cool down between) and topping off the coolant each time. You may also see the engine briefly run warmer than normal, poor heater performance, and gurgling from the dash. The official bleed process avoids all that, but I'm lazy so let it self-bleed and just keep a watchful eye on things.

On a related note, please be aware the temperature gauge is deliberately misleading. From approximately 180-230 F, the needle is centered. That is considered the normal range. To keep an eye on the temperature to avoid overheating if playing the self-bleeding game, it's best to read live data on a scanner.

 

well I just whipped the base of the water pump and re-sealed it. while I attempted to bleed it I felt the lower hose onto the heater valve ... (burning hot!), then the two pipes coming off the top .... barely warm (ambient temperature 34 degrees). The cars external temp display agrees .... 34 degrees in the shade, temperature control set to "max" ... and we have slightly refrigerated air from the vents. So as crazy as it sounds, both those heater valve solenoids must be stuck closed. Great......... that looks like lots of "fun" to get too

seeya
Shane L.

 

Be sure to follow the link in post #14 above. It shows a method to replace the DCCV innards without having to replace the whole thing.

 

So I bought a cheap heater valve on ebay (fingers crossed the very cheap looking junk works ok). Anyway, armed with anti-rollbar bushes and the new heater valve solenoids I figured I'd do the the rollbar bushes first. I quickly googled this job .... to make sure there wasn't anything to catch someone that hasn't done them before. It appeared to be straight forward. There was a youtube video that showed just whipping out the intake pipe and unbolting the left hand bush from above .... Weirdly they said nothing about the right hand bush....

Alll I can say ..... is holly ****, I'm glad I was pulling that heater valve out either way.





There is no chance they changed this bush in that youtube video. This is the heater solenoid/valve mount. It completely enclosed the rollbar bush bolt. You MUST remove the heater valve to do this job. Its kinda fortunate I guess, this is the main job I wanted to do.




They looked fine, and I couldn't see how they were possiblyl "knocking" against anything. The rattle that drives you crazy must be the anti-rollbar hitting the rubber bush. Because now with the new bushes in, she silent .... finally ..... I measured the heater hoses and whipped up and purchased that hose disconnet you see in the picture above ....... Yeah, don't bother it doesn't fit.








So I just unplugged all of the hoses, the plastic tabs fortunately didn't break off on the quick release connectors. You can just squeeze them with your fingers to release. The bottom most one was a pain, you have to be far more aggressive than I'd like to be with frail old plastic stuff to get it unplugged (twist the hose right around out of shape). Then you just need to work out how to wiggle the valve out (it will only come up and out in one position that I could work out).

I then just marked the unmarked hoses with a paint pen to make sure the hoses went onto the new heater vavle in the same position and refitted. Now we have heat as well as no rattling

I think I'm done with this car for now. next time its serviced I'll do the serpentine belt, air clean, spark plugs, fuel fliter etc (who knows, they could still be the factory fitted items fitted). Well I did check the air filter and it looks ok. I probably should check if the car has a cabin filter too.

 

Man great pictures and a great repair!
Many thanks for your work. That front sway bar bushing has been a tough one for a long time too.

You ran into the main problem with the internet. No barriers to entry so any idiot can post what he considers "facts" when it's all BS and they are just trying make a money on you tube! There is no referee to say hey that's wrong and stop posting junk.

AI is another moron item that people use so they can pretend to be smart. But they are just lazy and have disengaged their brains.
Threads like yours are what make this forum so valuable to people who actually work on their cars!
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I've taken the liberty of composing a follow-up message for you. A few months from now, just copy and paste to save yourself some time while setting up to replace the DCCV again:

"Hey everybody, I recently replaced my DCCV. Instead of choosing a respectable name brand, I went with Fling Dung because it was only $30. Oh well, lesson learned. Anybody have a brand they'd recommend. Why didn't I listen to Karl? He's so wonderful. I bet he smells nice, too."



All seriousness aside, I hope your new DCCV holds up. I'm willing to gamble on cheap parts but only based on two important criteria:

How difficult is it to replace? As lazy as I am, I don't want to repeat a difficult task twice. My laziness beats out my cheapness.

What are the consequences if the cheap part fails? Will it leave me stranded or cause other damage?

The DCCV is miserable to replace, as you have already discovered. That's scenario #1. Unfortunately, a bad DCCV can also damage the control module, primarily on 2003+ models, so hopefully scenario #2 won't apply to you.

Don't mean to jinx you, as I certainly hope this works out for you.

 

I was hoping I'd be able to dismantle and rebuild the old one. I'm thinking it probably just needs new Orings or similar in it. We will see .... Hopefully the replacement lasts for a while

Oh, and did I say that was if for the car for a bit. I moved it out of the shed last night and wound down the windows ........... sigh ....... No, where are those window winder rebuild kits that actually work again ....

I was a bit dissapointed I couldn't find a V8 S type in nice condition to buy. with petrol doubling in price in the last week, suddenly this seems to be quite a good thing.