Greetings!
2005 4.2 V8 Stype 88,000 miles
AC just started to not work intermittently. About 2 weeks ago it first started not working - blew hot air in LO. I shut off the control module and when I got home I turned off the ignition, waited a bit then started the car and turned the control module back on - AC worked fine. This morning I started experiencing the same issues. I did notice that the outside air temp on the module seemed to be off approx. 10 degrees F [shows hotter than actual ambient temp]. I can hear the compressor switch operating so after reading various threads and links I decided to swap the control module [previous owner had installed a new module a few years back and worked with the company that produces them so he got a second backup that he passed on to me]. No change noticed - [relatively easy procedure though]. As the AC does work from time to time and blows cold I am thinking either a sensor has gone bad or the DCCV [dual climate control valve] is sticking.
Any thoughts out there before I start to dig in further. I also thought I would try the broom handle tap on the valve as a few have already mentioned in previous threads. I did have the transmission cooler lines replaced recently - could this have affected something? [I know I'm reaching here]
Thanks in advance,
Gerry

 

99% DCCV. It will fry the module so fix (change) it soon.

 

Is the DCCV available as Lincoln part ? [2005 4.2V8] Are they the same on V6 & V8 engines? It appears to be the newer 3 hose type.

 

I did manage to disassemble the original CCM and visually inspect it. Nothing looks fried and no smell so I'm thinking it's most likely the DCCV as JagV8 stated.

 

Check the expansion valve on the firewall when you lose cooling. If it is frozen, you have a faulty temperature sensor at the evaporator. If it is not, DCCV as said above.

 

Your compressor could also be on its way out. Intermittent operation gradually getting worse and worse (especially as the weather warms up) is one sign of that in these cars. Happened to my 2005 S-Type 3.0 in May 2009. A new compressor resolved the issue....

 

Does the expansion valve that "Leaping Cat" mentioned have another name? Where on the firewall is it located? How would one go about checking it and/or the temp sensor at the evaporator"
The compressor appears to be operating normally - It is not getting worse and worse, I either get full A/C operation or it blows hot/warm air.
Whatever the problem is it will now have to wait as I am off to Chicago to see what is rumored to be Iggy Pop's last tour!

 

Look at JTIS - the free download workshop manual.

 

Forget the AC until you are sure the DCCV is operating correctly. If it has not been changed out do it now. They will almost always fail. It's close 100%! Yes there are 3 and 5 hose versions of the DCCV and yes the Lincoln LS part is the same.

Have you checked the heater hoses? Are they warm?

Have you flushed and changed coolant? It's needed and you should do it when changing the DCCV. Now your car is old and the cooling hoses need replacing so plan for that as well.

After that look to see if the AC compressor has any green/yellow staining on the bottom. Maybe even one or two drops of oil. These compressors are known to develope leaks in the case. The oil is pushed out first before any gas is. So it gives you an early warning to replace the compressor. Now the good thing about this is your car uses a very common Lincoln LS compressor. So easy and pretty cheap to get.
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Hello Gerry,

Here are a few quick troubleshooting ideas to help isolate the problem. Hopefully you can get the AC to act up again on a somewhat regular basis. These checks are designed to be done while the AC is blowing warm:

1) Try manually setting the temperature control panel to LO. This bypasses much of the automatic functions and will help rule out a bad input from the climate control system.

2) Look at the center of the pulley on the AC compressor. If turning, this tells you the compressor has been commanded on. If stationary, the command signal isn't being generated, isn't reaching the compressor clutch, or the clutch itself is intermittent.

3) If the center of the compressor pulley is turning, feel the expansion valve. I think this is located at the center of the firewall, directly behind the engine. It should be cold, but not covered in frost. If cold, this tells you the underhood portion of the AC is working, and is capable of putting out cold air.

4) Feel the pipes between the DCCV and the heater. If hot to the touch, this means the DCCV is letting hot coolant reach the heater, and negating any cool air being created by the AC system. Discerning the pipe temperature is a bit tricky, as they also heat up from ambient underhood heat. Try manually setting the temp control to HI and you should be able to feel the temperature increase as hot coolant is routed to the heater. If no change, most likely the DCCV is already open when it shouldn't be. This could be caused by a bad signal, or a stuck valve. Please note the two internal DCCV valves are spring loaded open and power is required to close them.


Try running these simple tests and report back. This should help know which direction to proceed.

 

To locate the expansion valve you have to follow the a/c tubes to the firewall - it is a small metal brick with one inlet and one outlet tube. And you just can see the ice on its surface or not.

 

You have the V-8 so even seeing the expansion valve is a trick!! Pray that you do NOT have to swap this! Good thing is unless you have some debris get in it they are very trouble free.

Here is a picture but yoiu really can't see it with the motor and everything in place. This is the V-6 version.






Also attached is a set of DCCV instructions so you can see what's involved with that.
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Ok, I'm back from a short vacation and ready to start the project. A big thanks to everyone who has given advice so far.

JagV8 was correct..... left unattended the DCCV will fry the CCM and it appears it did [lucky me I have a spare to work with and I may try my hand at the repair]. By the way it does get quite warm in the cabin if you drive it this way.

Clubairth1 attached a file that gives a step by step procedure for replacing the DCCV which seems extremely informative and should be a great help.
It appears that I will have to drain the system before the part replacement and then fill and bleed the system. Seems a shame as the coolant was flushed and changed less then 10K miles ago. I don't suppose it could be collected and reused? Not trying to be cheap but is seems to be waste to have to dispose of it. The manual says the system takes 10L/21pt of 50/50 orange extended life coolant with a WSSM97B44D spec. My question is will it require this much when I perform the replacement, what is the recommended off the shelf coolant and should it be bought premixed? [I assume the 10L spec'd is 5L of coolant and 5L of water?]

From my search of the forum it looks like the motocraft or 4 season/Autozone/Murray part is the way to go at least price wise. Has anyone had a bad experience not using genuine Jag parts for this application?

As a final note a friend recently told me that if I want to drive a Jaguar all the time I should buy 2 so I have one to drive when the other is in the shop or on the stands...... Seems like sage advice - have not heard this quip before.

 

Reuse if you like. (Filter out / decant off any bits.)

 

The old adage I've heard for 40 years or so about Jaguars is that if you drive one, you should always have a tow truck hired to follow you around....

No reason not to re-use your existing coolant as long as you screen it properly before adding it back into the system. I've done that on both of our Jaguars with no issues....

 

First yes reuse the coolant as was posted above. Not cheap just common sense. Only use what you need.

The coolant in your 2005 is just plain old Dex-Cool. You can get it anywhere and just look for the price. Walmart maybe?

I only use the 100% strength and then mix with distilled water but you certainly can use the 50/50 pre-mix too.

Now be CAREFUL around the top tank. The nipple is very easy to break and at this time it maybe already broken. Not a huge deal but about $140 new. I would only use the Jaguar part. Be aware you will be replacing this if you have not already. Just a wear part that degrades with time.

The bottom of this tank has a large diameter coolant connection with a odd snap-wire retainer. DO NOT loose this piece of wire! It snaps in and out of position but can easily fly off into who knows where and we have NOT be able to find this separately! Also be very sure this connection is secure. It's in a bind when installed but when coolant pressure builds it will blow the hose off the nipple. This has happened at least once on this list and the giant coolant leak will over heat the engine in seconds and your temp gauge will never move.

Finally I don't see where you are changing the thermostat and I would add that to you repair list. Again I prefer factory but others have used aftermarket ones. It's a bit fiddly as the UK guys say so make sure you get the jiggle valve in the right position. 12:00 straight up I think? Also be aware of the rubber seal and the direction the thermostat is installed. We have seen them installed backwards before!

You don't have the STR and the NA V-8's have much more plastic in the thermostat area and it all decays with time. You may need to change some of that. For some reason Jaguar did it right on the "R" and everything in that area is all cast Aluminum. Thank God!!

Just remember that the tow truck and Lucas prince of darkness jokes are the reason you got such a great deal! Now after 6+ years and around 100K miles of owning an STR I have found the cars to really be no better or worse than other brands. Just less common so harder to get a proper repair. It's not a Chevy for sure! But you found this forum and it's all in here you just need to find it!
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By top tank I assume we are talking about the "Coolant Reservoir" or coolant expansion tank ? This was replaced by the previous owner but I have read that they fail with time so I will be careful and inspect it. I have read that the OEM part is the only way to go on this particular part.

The instructions that were in the attached file for bleeding the system after reassembly say to remove the coolant expansion tank bleed screw then fill the system with fluid then carefully tighten the bleed screw. I sure this will make sense when I am doing the job - is it to equalize pressure when filling the tank?

The thermostat was replaced 64 miles after I purchased the vehicle [less than 9K miles ago] when the thermostat housing failed and dumped all the coolant. As it was the first day of ownership and I was not familiar with the vehicle or the forum I took it to a local shop that specializes in high end European vehicles [at surprisingly affordable rates]. They replaced the necessary parts and a number of hoses that also failed along with new gaskets and new hoses under the manifold [already there why go back later]. The PO was a great guy and picked up half the cost without being asked [called him for info and he felt bad]. I wish I would have known about the aluminum parts on the "R" as I would have upgraded at the time. For future reference - do they fit on the NA V8?

Probably a wise move to inspect all the hoses as long as the system will be drained.

Off to buy parts today along with a 45 degree hose clamp removal pliers which I have heard makes the job much easier. I usually use a small pair of lock jaw pliers that have wide jaws for dealing with hose clamps but it seems like a small investment for a worthwhile tool. Planning on doing the job tomorrow as we are expecting temps in the high 50's low 60's and it will give me Friday to source additional parts should something go wrong.

 

Good deal on the thermostat. One less problem.

No can't use the "R" stuff on the regular 4.2L.

The nipples are very weak even when new. I would not remove the coolant bleed screw or even mess with it. Another part that is easy to break. I just let the car cycle from hot to cold several times and just keep topping up the coolant. Some people have had problems bleeding but try a few hot cold cycles first.

I use cable pliers on the hard to get to hose clamps.
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I'll try not opening the bleeder as you suggested - seems wise.

I found that the shop that did the thermostat used Pentofrost SF so if I am reusing coolant I'll just pick up a 1.5 qt container and mix it as/if needed when I get the motocraft DCCV from S-G import that I ordered tomorrow. $128 - way less than Jag [$383] or Lincoln [$203] or even O'Reilly[$145]

 

OK quick update: I installed a new DCCV yesterday. Not that bad of a job laying on your back but a hoist would have made it much easier. I found carefully removing the coolant recovery tank and the main radiator hose on both ends and at the DCCV made the access a bit easier. I was able to get at the retaining bolt with a small 8mm socket with a 2'' extension from above - I also removed the top 2 hoses on the DCCV from above at the DCCV. Hoses were all in good shape as was the tank and nipples.

Now the question: The new DCCV solved the full heat seeping into the cabin but it appears the CCM is shot as is the spare that I had. Neither will turn on. I do have power to the illumination behind the red and blue hot/cold indicator buttons when I turn on the headlights. I also noticed that the rear window defroster will not engage.
Does this sound like a typical "fried" module?

I am thinking about sending one/both units to JaguarClimateControl.com for repair. They claim that their repair will supersede the original spec and prevent this from happening again when the next DCCV fails in 3 - 5 years.

Has anyone had experience with this company that they would care to share? Is there an alternate source for repair? I'm leery of just purchasing another new unit if it's just going to fail again and used seems to be a crap shoot.