Look at these 4 files on the heater hoses :
PDF file showing Heating hose system schematic diagram and description of how the heating hoses system works, also Part numbers listing:

https://www.dropbox.com/s/71ui8mxn5f...6%20List.pdf?m

Here is JPEG file with photos of the water valve:

https://www.dropbox.com/s/0vn3eh8h6o...20photos.jpg?m

Another JPEG file showing a different view of heating hose system (includes some photos of the auxillary heat water pump, non-return valve and heater bypass with another non-return valve):

https://www.dropbox.com/s/0vn3eh8h6o...20photos.jpg?m

Here is a JPEG file showing the Heater Feed hose and the Heater Return hose, also has their part numbers:

https://www.dropbox.com/s/uope7mfk7k...rn%20Hoses.jpg



Jim Lombardi

 

Smoke is definitely an option - I also think I will invest in one of those dye-based exhaust gas testers. It might tell me something I don't want to know, which is my hesitation. I'm also considering buying a UView Airlift, which vacuums out the entire system - kinda of the opposite of a pressure test. When you're done, you put the thing in a vat of new coolant and it gets "vacuumed" back into the system, keeping it free of air pockets. Supposed to work really well, both as a leak tester and a system filler.

Thanks much Jim, especially for that PDF. I think I am going to invest in a bunch of the harder to get at hoses, and when I drain all the distilled water out of the system just get to replacing. That PDF makes finding that part numbers MUCH easier! I need to get a couple new belts too, and maybe a tensioner or pulley (something squeaks when cold) - gonna be a fun box of parts.

I put another 20psi in it last night for several hours and found no leaks, though it lost another ~.5psi over the course. This morning when I started the car, there was some white smoke from the exhaust for a minute or two which concerned me, but there was also an unseasonable collection of condensation all over the car (and all the other cars), so perhaps the smoke was just water that had condensed in the exhaust. It has never smoked before, but it's 90+ degrees here. I seriously almost started another car to compare, but time was short.

The car just turned 106k this morning, so I'm just gonna drive it for a couple hundred miles and check back on the coolant situation. This is the second strangest problem I have ever had - the first being an alternator problem on an '88 Saab 900T back in 1999 that I never ended up solving. Good times.

 

Thought I would follow up on this - because I don't think it's solved...

Between that last post in early August and the beginning of October I added another 1500 miles to the car. During the time, I did not check the coolant tank once, never got any warnings about low coolant. If there was loss, there wasn't much.

The first week of October I drove it from Sacramento to Hercules, which IIRC is about 70 miles. At around Mile 5 the Low Coolant warning appeared, which I IGNORED. Within a mile it was gone again. During the next ~65 miles the warning appeared perhaps three more times, each time clearing itself within a mile.

After spending about four hours in Hercules, I checked the reservoir tank. It was essentially full, close enough to where I'd left it that I couldn't tell the difference. I put a splash of Fuji bottled water in it for good measure and drove it home without further incident.

Over the course of October, I added perhaps another 100 miles without any more warnings. Today after starting the car and driving maybe a mile, another Low Coolant warning, which disappeared again in SECONDS. I did my driving, no more warnings, got home, let it cool, and checked the tank. FULL. I checked the overflow in the fender - nearly, but not quite, empty.

So, some things:

1. I can still find no evidence of a leak under the hood. Places that had previously been wet are now dry, and pools of Dexcool goo are slowly burning off. It's simply never damp under there any more. However, sometimes after driving I get a whiff of coolant smell from the driver's side of the engine, but I've been attributing it to Dexcool burning off - there was *quite* a puddle under the supercharger on that side of the engine.

2. I think it's safe to safe the system is reasonably well sealed, as the car has managed to vacuum up the previously full overflow tank in the fender...

3. ... of course, that makes me wonder *why* it's needed to vacuum up the overflow tank, as that implies water in the system *is* going somewhere and needs to be replenished...

4. ... unless there were pockets of air trapped in the system that have slowly bled out... which might explain why the intermittent Low Coolant warning. There were previously three "mid system" leaks that *certainly* could have let air get sucked in.

5. I added about 6oz of distilled water to the reservoir tank this afternoon, which brought it from where it normally is to totally full. I expect that 6oz will end up in the fender overflow, but if it doesn't, then I think I have real reason to be concerned.

Bottom line is, I have no idea what's going on. I ordered a dye kit from Amazon which will be here tomorrow, maybe that will allow me to see a leak somewhere. I also can't - unfortunately - rule out the possibility of a slight head gasket leak, or maybe a heater core leak. We'll see what the dye says.

 

My guess is a hairline crack in the header tank, they fail more frequently on the XKR, I guess because of the cramped quarters.
The leak appears when the system is heated, opens the crack and when cool it seals. Fairly common...look for a cheap spare or new and see if that sorts it, also sounds like you've a sticky coolant level float. The rod it slides on firs up, sliding the float with your finger usually gets it back to operational.
Hope this helps

 

Congratulations on joining the club! You will find Ebay to be a great source of inexpensive parts. Auto Enginuity with the Jaguar enhancements has dealer level
OBD2. Even does airbags. Coventry West near Atlanta for parts you can't find on
Ebay. Replace every coolant hose and you will have tremendous piece of mind.

Sunex® Flexible Hose Clamp Pliers, 3720 or the OEM brand equivalent with save
you a lot of time with the limited access.

Pliers & Vise Grips | Specialty Pliers & Kits | Sunex® Flexible Hose Clamp Pliers, 3720, Locking Clamps, 24" Long Cable | B982803 - GlobalIndustrial.com

Do not use K&W NanoTechnology Permanent Head Gasket sealer. It won't stop a leak and WILL block your heater core. They do not honor their warranty even with a replacement engine receipt. Fixing leaks with hard work is the only way that will work.
Download JTIS and follow the instructions on the website. Manuals are hard to come by. Ebay has some "parts" manuals that are actually just pages out of a collision repair manual. Better than nothing.

Good replacement cup holders are about $125. Cheap quality, but not cheap price.
Worth it to avoid the aggravation. Spend $$ on the important stuff first though.
Took me about $8,000 to get my $3,000 car to be reliable. They are like a horse,
you have to enjoy taking care of it if you want it to last.
Good luck

 

I used the K&W Block Seal on a 93 Thunderbird with bad head gaskets. The repair lasted less than a day. Then, I tried a product called K-Seal. It was much simpler to use, as it mixes with anti-freeze so you don't have to flush the system first. When I sold the car 7 months later, the head gaskets still didn't leak. And, K-Seal doesn't clog the heater core, either.

That being said, I wouldn't use any product like that on a Jag. But, on an old beater, K-Seal is perfect for squeezing a little more life out of the car. One of our customers has a Dodge Caravan that is still going, three years after we sold her a bottle of K-Seal for her bad head gasket.

 

Could be just the sensor playing up, there was a post here about 2-3 months ago detailing a member's saga with that problem.
I would suggest getting a realgauge kit from
RealGauge FAQ - TheJagWrangler
which will show you the actual temperature of the coolant, then you can ignore the warning light, and trust the gauge.
Several members have installed the kits, they are easy to fit, and good quality.

 

Fairly certain it's a leak now, but I can't tell from where.

Dropped some UV dye into the reservoir and sat around waiting... for nothing. Drove it around for an hour or so, and found dye trailing down the driver's side of the transmission. I cannot tell where it's coming from, only that it's dribbling down the O2 sensor wire and onto the transmission. The only clue is on the part of the octopus hose that travels across the transmission - it looks like its sweating dye. I don't think there's much else going on there with the cooling system, so my best guess is maybe a pinhole leak in that crossover that's only a problem under high cooling system pressure? I dunno.

I think I am going to order a replacement octopus hose since it can't hurt to replace anyway, and maybe that will either cure it, or I'll find some other issue in the process.

Anyone have any other thoughts or ideas before I get going on my theory?

 

For the princely sum of $270, I bought the world's most expensive heater hose. For grins I sent it out for a metallurgical analysis to confirm it's not made of gold. It's not. It's just really, really pricey. I also bought the small plastic tube that runs from the header tank to the crossover pipe, and the tiny plastic tee that connects said most expensive hose to the rubber hose that runs under the supercharger. Grand total was just over $300 after tax, but I'll sleep better knowing there aren't kludged parts holding my car together.

I drained my cooling system, refilled it with distilled water, ran the car, drained it, refilled it with water again, ran it and drained it, then started in on the hose. I expected torture, since expensive parts tend to come with torturous install procedures, but honestly it wasn't bad. Absolute worst part was removing and installing the small branch of the hose that connects to the bottom rear port of the electric (heater?) pump, as access to that spring clamp quite frankly sucks! Whole operation, minus my half-assed flush procedure took maybe 1.5 hours. Another 30 minutes for the flushing, and probably another 30 for cleanup (I am sure my entire driveway will now glow under a florescent light). Really, not a big deal to replace this hose. I refilled with Prestone Dexcool - I have a thing about sticking with manufacturer specifications wherever possible. Sadly, remnants of the dye I used immediately turned the orange stuff green again.

I like to thank Safi for the post about replacing the hose (https://www.jaguarforums.com/forum/x...-repair-93451/) - although pretty straightforward, the fitting on the passenger side confounded me, and that DIY probably saved me an hour of time that I would have spent staring at the coupler. Heh.

Now, to see if my car finally stops disappearing coolant, so I can focus on important things like the lack of a left radio channel. Oh, and maybe do some driving, too! That'd be pretty neat.