Thanks for the additional input, guys. You're schooling me in A/C operation and it is much appreciated as I attempt to get this issue resolved. As previously mentioned, I'm calling the body shop when it opens later this morning in an effort to get them to take this issue more seriously. I question whether they truly took the time to inspect and monitor it properly last week, seeing as their A/C test equipment was having problems (or so they told me). And I believe that if they had installed a new receiver/dryer, they would have told me that. Also, the system was blowing its normal icy temperatures up until a couple of weeks ago so yes, I think it was working normally after the accident repairs until then....

I'm going to approach this issue from the standpoint that "You guys disassembled the system last year as part of the repair process, we appear to have a leak now, so please take this very seriously and diagnose it with the necessary time and attention it needs. On 80-degree days and hotter, the car is undriveable for my wife in her business attire."

We'll see what happens....

 

You'd lose the bet most of the time as the common faults are: coolant leaking out through the DCCV or from the expansion tank or from the hose joints.

 

Good trouble shooting and post but your conclusion is wrong. There is a huge record of DCCV failures for both the Lincoln LS and the Jaguar S Type. I have both cars and both DCCV's have been replaced because of leakage and/or heating/cooling problems. You are the first I have ever heard of burning the 12 VDC connection at the DCCV plug??
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Update:

I spoke with the body shop this morning. They swear my A/C system held a vacuum for a full two hours last Friday and was properly evacuated and then recharged completely to Jaguar's specifications. They firmly believe they added the correct amount of 134a into the system....

I also spoke with a good contact that I have in the service department of our local Jaguar dealership. I've always trusted him because he's given me excellent advice from the time I was researching this car prior to purchasing it. Just wish this particular dealership didn't charge twice what other Jaguar dealerships in our state do for parts and service. After describing my problem to him in detail, he suspects a 134a issue as a first step towards resolution. Could be undercharged, could be overcharged, or there could be a leak although he is puzzled how the system would hold a vacuum for two hours if a leak is present. He also talked about potential condenser, evaporator, and sensor issues. He has yet to lay his eyes and hands on the car for this issue however, so he is reluctant to speak in definite terms. I can certainly understand that....

I think that the body shop will wind up making an appointment for the car at the local Jaguar dealership. As long as it is covered under my body shop warranty, I'm good with that (a failed condenser, an improperly-charged system, a leak they missed, etc.). But if the problem turns out to be something new that the body shop will not take responsibility for, this could get very expensive given our local Jaguar dealership's propensity to charge double rates for everything....

 

Update:

Did not hear back from the body shop by mid-afternoon so I decided to take the car to a well-respected shop in Raleigh for an independent diagnosis of the A/C system. The result? A failing compressor. Hard to believe that a 5-year-old S-Type with just over 46,000 miles would already be having compressor issues. I don't think I've had a compressor fail in ANY of our vehicles in the past 25 years. I'm still somewhat stunned since I was not expecting this....

So a new compressor, a new receiver/dryer, a proper A/C flushing of all lines including the condenser and the evaporator, a new charge of 134a, and all labor involved will come to just under $1,200. Our local Jaguar dealership would charge more than $2,000 for this....

These guys are 100% confident it is the compressor in the early stages of failure. Inadequate system pressures after evacuation and recharge indicated such. They'll honor my AAA Motor Club discount and provide me with a 2-year/24,000-mile warranty, which I believe is twice as long as Jaguar's warranty if the dealer did this job. All new parts, nothing remanufactured....

I haven't pulled the trigger to go ahead with repairs yet - I want to do a bit more research although I acknowledge I'm no A/C tech. Anybody else have any thoughts here?

 

Jon,

So the situation is as I suspected, a lack of pressure at idle...

Let's assume two shops have confirmed the proper charge. AND the car holds vacuum, so there is NO leak.

Are you 110% sure the belt has the proper tension on it. I have NEVER seen NOR heard a compressor failing via the method of reduced output. Is the compressor quiet? Any bearing or belt noises? Every one I have seen fail has either ceased, or chewed up a bearing, and made a hell of a lot of noise when it was on it's way out.

If that's the case, and it is failing, It's time to look for Lincoln LS parts. I can almost bet you will be half the cost of Jaguar ones. You think they use a Jag specific A/C compressor, but the same DCCV?? I dont....

Just food for thought.

George

 

Agreed. There's no trail of people with failing compressors on the S-Type.

If (and that's IF) it's failing might it have been due to the original accident? (Sorry, can't recall where the car was hit.) It would have had a jolt.

George's ideas are good. Also, I think a magnetic clutch is used to engage the compressor so that's another potential failure point. It'll be separately changeable. Again, an LS is likely to use the same part. An online parts place may be the best way to figure it out.

John

 

My on-line research late yesterday confirms that our S-Type 3.0 uses the same compressor as the Lincoln LS. Omega (omega-usa.com) has a large presence in the automotive compressor distribution market - they offer the same compressor for both the S-Type and the Lincoln LS. The problem may lie in convincing an A/C shop to install a part that they don't source (and mark up) themself. They certainly won't warranty it....

My serpentine belt seems to have proper tension on it and appears to be in good condition. I've installed replacement serpentine belts myself on my Ram and on my wife's previous Lexus SUV in recent years, and I'm accustomed to a "give" of perhaps one-half inch when pressing down on the belt with my thumb. I assume that's proper for the S-Type as well. If it is not, speak up please....

Standing over the engine bay with the hood open and the engine idling, I do not hear any unusual sounds eminating from the compressor. But that component is down at the very bottom of the engine bay. It may sound quite a bit different with the car up on ramps with the undertray removed and me lying on the ground listening to it through my mechanic's stethoscope. I will do this today before making any final decisions on how to proceed....

The compressor's clutch is engaging when the A/C system is turned on. Keep in mind that the system cools the cabin, just not very strongly or efficiently....

Yes, I've thought about the compressor potentially being damaged by the jolt that occured when the car was front-ended last August. The A/C was running at impact. It continued to function as I drove the car home after the police finished their accident investigation. Could that jolt have taken this long to finally cause the compressor to begin to fail? Was the A/C system improperly evacuated and recharged during accident repairs after the condenser was replaced, and that improper charge has now caused the failure of the compressor? Who knows? I thought there is a pressure relief valve in the system to prevent overcharging from causing compressor damage, but perhaps I'm wrong about that....

So George, how do you obtain definitive proof that the compressor is indeed failing? If it is in the early stages of failure as described, it is possible that we cannot hear it yet....

 

Just spoke again with my trusted contact at the local Jaguar dealership service department. He was not at all surprised that the diagnosis is a compressor in the early stages of failure. He has seen this issue primarily with X-Types, but also with S-Types as well. He has worked for Jaguar for more than 20 years....

 

Yes there is a over pressure valve. It will usually "pop" at about 450 psi. After reading you long story I still think the accident is the root cause. I just don't see the S Type or the Lincoln LS having compressor problems with the miles your car has. Of course it could just be your lucky number too!!
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Jon,

This is where a good relationship with an independent mechanic comes in handy. Granted I'm spoiled in having a shop in the family, so I have access to whatever parts I want at cost, but beyond that. Any reasonable mechanic should be willing to install whatever parts you specify. That being the case, you may even think about a DIY repair here. Having the system evacuated, then recharged when you are done...

As far as I know there is no pressure relief valve - Remember the EPA ****'s have made it illegal to release even non HFC refrigerant into the atmosphere. What there is is a pressure shutoff valve, if pressures spike, such as would be the case in the condition of an overcharge, it will shut the A/C compressor down before it bursts a line. I really want to know idle and 2500 rpm high and low side pressures here. I think there still might be some sort of undercharge issue. I just cant see a perfectly quiet, working compressor somehow losing some of it's efficiency. The clutch may be an issue as well, THAT could cause an underdriving of the compressor. Jon, once again, In all my experience I have never seen a compressor failure manifest itself in the matter you are describing. It either working while sounding like there are marbles in it, or not working / ceased.

Do yourself a favor - when the compressor is engaged, look at the clutch plate -compressor side - is is spinning at the same rate as the pulley? Hint a couple of dots of paint and a timing light work wonders here. If not that may be the issue. I wonder if the clutch is available separately?

I really don't know about belt tension specifics on the S-type, I assume from your post that the A/C compressor is on the serpentine belt, and relies on the clutch to engage / disengage it?

Definitive proof of the compressor failure - once you are CERTAIN that it's driven at the proper speed, is a proper low side pressure - (think of this as the input), combined with a weak or low high side pressure. An elevated low side pressure will show some sort of internal leak in the compressor - basically at rest (compressor off) low side and high side equalize.

Honestly Jon, and I know you don't want to hear this dirty little secret... I'd add a bit of freon to the system. I bet you it cools the car down. Since the compressor can do a semi decent job of cooling at speed, all you need to do is raise the input pressure to get the output pressure to the right place. You wont hurt anything.. There are failsafes built into the system to stop it from dangerous pressures. (and they are on the high side). Sure it will strain the compressor a bit more but if it's on it's way to compressor heaven, then so be it, I can almost bet you will buy yourself time.

The key here is get the car on the gauges. I think autozone / advanced auto or whatever flavor of parts store may even rent them.

Take low and high side readings at idle with A/C on max, and with the engine at speed.

George..

 

That sounds plausible tension on the belt - there's a spring-loaded tensioner (see p117 of that PDF of Vehicle Specs I posted).

Sorry, but I've no idea how long a compressor might live on if it had been damaged or the system underfilled. Realistically if it's the compressor I think you'll never know why it died but probably will have to pay yourself

Be careful when you're under the car with engine running!

 

If you add R134a, I'd avoid the cans that also contain so-called "safe" sealant. IMO it's NOT safe but MAY ruin an otherwise working system.

That p117 I mentioned shows the compressor is on the same belt as most other things (alternator ("generator"), water ("coolant") pump etc).

I believe the clutch is available separately and I have a dim memory of a TSB involving the a/c clutch.

John

 

I completely agree, you want straight R134a - no additives, leak proofers or any of that crap at all.

I just checked, the clutch is available in 3 parts.

The coil (engages / disengages the clutch). - Motorcraft - YB595
The hub - Motorcraft YB594 - Possibly superceeded by YB3124
And the pulley - Motorcraft YB592



Taking a look at the Compressor with clutch installed... What you want to do is mark the belt relative to the pulley. If there is belt slippage, the marks will come out of sync. You're not going to really be able to determine the input shaft speed v/s pulley speed. I don't THINK.

George

 

George, there's no way I'm going to DIY any component in my HVAC system that requires an evacuation and recharge. I doubt if the reputable A/C shops around here would even touch that - too many critical elements for Joe Shade Tree Mechanic to screw up. Plus, I want a warranty for this critical part of the car (my wife won't drive the damn thing without arctic-capable A/C and when it's 95 degrees outside and she's in business attire, I don't blame her one bit). 2 additional years or 24,000 additional miles is worth some additional cost to me. This A/C system being diminished has essentially parked the car in the driveway for the past couple of weeks. This S-Type does me no good unless she's in it as her primary vehicle during the workweek since it operates for only 60% of the fuel costs required by her Lexus SUV. I gotta get it fixed - the longer it sits, the more gas money she's spending to roll around in her SUV all the time....

 

Jon,

I completely understand your position and respect it.

I guess you and I have a bit different perspectives on the subject in some ways. I'm not married, and have a 2nd car available (as do you fortunately) if this one gets laid up... I'm much more of a toy and tinker guy. Maybe it's the engineer in me... who knows. The warranty seems to be of negligible value to me in this situation, especially knowing that even a reman compressor will outlive it. Basically the warranty only covers the possibility of an initially botched repair, or poor quality replacement part. (I am assuming it only covers replaced parts). I also don't think the A/C is as sensitive a system as some make it out to be.

Now, before you go dropping $1200 on the Jag Branded Compressor and install etc, lets see if we can get this thing diagnosed 100% correctly. I would seriously talk to the shop about Lincoln parts as well... I have NO doubts that a new compressor, complete with new clutch will solve the issue. And the $35 (at least motorcraft branded) reciever / dryer makes sense anytime you open the A/C lines to outside air.

My questions are:

Is the belt tension proper, and is the clutch ok? - The clutch IS externally replaceable. And are we 1000% sure the car has the proper charge. Only the gauges will really tell us.

Mark the belt and pulley. See if the belt slips.
Check the pressures high and low.

As far as this somehow being related to the accident - my only suspicions there would be if the dryer held moisture that couldn't be boiled out with a vaccum and it wasn't replaced when the condenser was. (but this would manifest itself earlier) - If the condenser was in fact compromised, and you ran the A/C post impact you certainly put some outside air in the system - or at least exposed the system to outside air. - You were probably leaking refrigerant mostly though. (Unless the condenser was damaged in a way that did not create a leak in the system).

The other thing would be potential misalignment of the pulley, or slight tweaking of the clutch hub if something got pushed far enough back to touch the A/C comp. The other thing here may be a tweaked or partially kinked hard line restricting flow.

George

 

We've been a bit slow getting a/c over here (it's not so hot) but even so a full empty, vacuum, refill is about $60. They'd throw in doing the readings George mentioned for nothing, I expect, or do them alone for maybe $20-30. You gotta be able to get them over there for not much money, and then George will probably help you with what they mean

Replacing a compressor DIY should mean paying for removal of gas and later for vacuum & refill. I'd just pay to have the whole job done LOL - if it needs doing.

 

The problem here is 2 fold.

First, use of the Lincoln Branded Compressor v/s the higher priced Jaguar one - even though it's the same part. Second, parts mark up etc. You can get a brand new Lincoln compressor (which includes the clutch) for $254, Lincoln Reciever dryer for $35. = 289. Second shops here not only make money on labor, but also mark up the parts.

If you could talk an a/c shop into paying a little extra to evacuate first, THEN vaccum / recharge once you bring it back - say $120 you are still into the job for $410, and an afternoons worth of work. That's 1/3 the 1200 cost Jon was quoted.

Edit: I have no problem with shops making money, that's how my own brother feeds his family. And I understand the overhead, equipment costs etc involved. It's just also opened my eyes to how much cheaper it can be to diy.

George

 

George,

Where are you finding the Lincoln LS compressor and clutch assembly for $254 and the Lincoln LS receiver/dryer for $35? And what are the Motorcraft part numbers for these components? That may be worth chasing down myself, if the shop is willing to let me supply my own parts (and I'm sure that's a big "if" - most shops around here won't do that). I'll gladly pay them for their A/C expertise, equipment, and labor if I can supply my own parts. I think that's a very fair compromise from a total cost standpoint....

Remember, you're spoiled rotten by your brother's shop so your perspective is quite different from mine. The rest of us can only wish we had that kind of arrangement....