So, when I got this vehicle it was dangerously low on every fluid except oil, which looks fine and is at the proper level. Thankfully I trailered the car home so it didn't do any real driving in this condition, and as soon as I noticed it I corrected all the fluid levels. It was necessary anyway to troubleshoot some other issues I was having. Now I just finished rebuilding the transmission, and the rear suspension bits, and its been up on stands for probably 6 months. I didn't notice any coolant leaking when it was in my shop, but I also didn't check the coolant before I drove it over to the shop so its possible that the coolant had leaked out prior to that. Anyyyway - when I topped off the coolant after I got the car I just used water, temps outside were hot, as it was the summer, so I didn't worry about getting antifreeze. Of course its almost december now, and while i dont live in a place that gets super cold we do see temps down in the teens so it was time to think about antifreeze. I figured that I would just top it off with concentrate after draining a bit and call it done. I couldnt get the little drain valve to open and didnt really feel like digging into that at the time so I just popped a coolant cap off and figured I'd see how much it took and decide from there if i needed to work out draining the system to get a proper mix. It took the entire gallon of concentrate, and then another gallon of water to fill the system. Now since the oil level is fine, im obviously not getting any coolant in with the oil. The transmission fluid still looks that bright red that its suppose to so I dont believe the trans cooler failed. I've got some cardboard under the car now to catch drips so this question may answer itself, but is coolant loss like this a common problem? Is there something in the system that is known to fail that could account for it? I'd appreciate any thoughts you folks have. As a side note I can't do any testing with the car running right now because I am making a new injector harness and just removed the old harness.

 

At the top of this forum there is a sticky on cooling system maintenance and how to bleed the system properly. It's very important info, as the XJS has a lot of cooling system peculiarities that can cause trapped air.

Second, NEVER use just water. There are many dissimilar metals in the system, and corrosion can occur quickly and cause permanent damage. Jaguar specified at least 55% antifreeze to 45% water. Use a modern antifreeze specifically made for aluminum engines. I use Zerex G05 with distilled water.

 

The only question that you didn't answer has to do with how much you did or didn't drive the car between filling.

It's quite possible that what you thought was FULL, when you filled with water, wasn't even close. When filling these cars with fluid air bubbles can create LARGE voids,,, but 2 gallons worth? That's a lot. Are you able to remember how much water/coolant it took durning that first fill?

In my car, in the beginning, I had drips. One was over the manifold downpipe area on the RH side. Only dripped when hot and the water would be evaporated with contact with the hot parts and never make it to the ground. I could small coolant but not easily see it leaking. Took a flashlight and inspections while the car was running and hot.

 

Drove it a couple hundred yards over to the shop so I could get the transmission and irs out. And spent maybe an hour idling spread out over several troubleshooting sessions. At the time the transmission had lost reverse and I had a ton of vacuum leaks. At the moment I am pretty certain the water pump is leaking. I read that sticky when I first got the car but forgot all about it lol distracted by the massive transmission problems. Now that I'm getting back at it, and figuring the water pump is likely original equipment. It's gotta go. I'll work on making the new injector harness while I find money for the pump lol

 

Right on... Question: parked/stored on black top or concrete,,, or an absorbent surface?

 

Parked on dirt/grass/gravel mostly. The shop has a concrete floor but my garage does not and the driveway is gravel.

 

The places I can find these pumps all seem very pricey, 350 for a water pump is kinda crazy. I read somewhere that there are rebuild kits for these pumps but I can't seem to find one. Can someone confirm the existence of a rebuild kit and maybe provide a link to where they can be found? Or a more reasonably priced pump?

 

SNG Barratt has new pumps for about $155. I have one in my car. They may have the rebuild kit also, but pull your pump first, as it may be too corroded to rebuild.

 

Yup! x3...

 

Thank you ! For some reason I always forget to check there and they never come up in my Google searches.

 

never use water in any car. Always use distilled water. Tap water merely needs to be non poisonous to come out of the taps and not always that.
The other thing is people have been encouraged to put stop leak in the radiator rather than find the source of leakage in all the hose clamps and gaskets etc.
Doing so plugs up the radiator resulting in overheating. The best way to confirm the radiator is working properly is to use one of those cheap infrared temperature guns. $20-25 on Amazon and you just check the whole radiator over. The Jaguar radiator is a double by pass radiator and much more efficient at removing heat than cheap aftermarket aluminum ones. Even some expensive ones designed for Jaguars don’t have the double bypass feature.
That gun can also check the tune of the engine.
Very quickly by just aiming it at every exhaust port.
If all 12 cylinders are near the same temp, you are good to go.
Regarding oil. Do not be penny wise and pound foolish. Change oil based on time not mileage. Acids build up over time. It’s best if the car runs periodically and long enough to come up to normal operating temps. That helps keep clean fresh oil in all the places that need it.
One other thing. Because of the short stroke piston speed is way below normal. Thus rings tend to build up carbon deposits. Once the engine is fully warmed up run the engine to near redline to help remove those deposits.