Hello All,
2001 XK8, 100,000 miles
I have been loosing coolant for a while now. All new hoses, thermostat housing, water pump, etc 2 years ago.
No stain on the garage floor, no obvious leaks but definitely smell antifreeze. Probably leaking on exhaust somewhere while running. No milky dipstick or oil filler cap, clean inside valve cover. Car runs great.
I am buying a new coolant reservoir cap, cheap enough, thinking it’s bypassing to the line to the recovery bottle.
Anybody know where this bottle is so I can check? Any other ideas I can look into?

Thanks in advance for any help,
Jack

 

From memory, driver side wheel well, behind the plastic liner. Pull the wheel off, then go around the liner and remove all fasteners. There are 3 or 3 different kinds, almost like Jaguar engineers were testing how many they could get away with on a single part. Play along, though, easy job. You should then see the line from the top, as well as a line to side in case of overflow. Likely pretty dirty, take advantage of being there to clean it all up. Check for aged/cracked plastic lines.

There are other leak candidates: octopus hose ends, right on top of the cats, or the dreaded valley hoses, or even the overflow tank itself. From memory, the Harbor Freight coolant test kit comes with an adapter suitable for our cars. Not super cheap, but a pretty sure fire way of finding external leaks.

Best of luck, keep us posted.

 

If you buy the kit, it's the green one that fits the Jaguar.
Using that is the only way I found the one under the throttle body. Bad spring clamp, just moved it down the line and put in a screw clamp. Be careful if that is it, plastic connector under the hose.

 

+1 to Fmertz's suspected suspects

Jetjack,

When you say you replaced the hoses, are these only the hoses at the front of the engine?

For my 99 MY XK8, I did have an undetectable coolant leak for a while, and found it while under the car. It was the infamous Octopus Hose connections leaking. Fix is DIY - able and viewing from top is very difficult as it's buried by the bulkhead. It was made easier for me as I had the car up on a friendly mechanic's car lift.



Fit up as shown below. The Octopus is Part 1 in the Figure and the big arrows point to feed and return through the "Valley" of the DOHC engine.


Good luck on your search and let us know what you find.

 

Thanks all, I did replace the octopus hose and the valley hoses, every hose shown in the parts catalog, I believe wherever it’s leaking it is landing on some part of the exhaust from the smell

 

Jet Jack,

You obviously have cared for the car, but what about the hoses to between the heater core and the water valve.


Another possibility, as suggested by Fmertz above, is a leaking seam in the plastic bodied expansion reservoir.

 

I replaced the coolant reservoir tank cap and problem has seemed to have disappeared

Thanks all