Hello,

I got a long issue with my Jag and I dont see the end.

Back in october, I got a pipe that untie itself, releasing water, I though nothing of it, just retied it and pull some more water.
As we could expect, the issue came back, and came more pressing. You can drive 3 miles without issue.

What I did :
- Change the water cap, now I dont untie pipe, pressure got off the water cap
- Change the radiator, water pump, accessory belt, auxiliary water pump
- When I tested drive the car, I got the alternator out, then auxiliary water pump out, and out of current, the car eventually overheated and stopped...
- Did change the alternator, no more electrical issue got a good 14,3V when running.

On a normal drive (it's spring here about 20°C), the car will go up to 117°C and then get water off the cap in city driving without high reving or anything else...

But still not working, I did a react test off in order to see if I dont have any head gasket issue, but I dont think so...

Any clue of what may happening to the car ?

 

I suppose you have air trapped. After i changed radiator on both xj8 4.2and xj6 3.0 (same radiator)
I LIFTED THE CAR IN THE FRONT, FILLED UP WITH OAT G12+ SILICA FREE OVER THE COOLANT EXPANSION RESERVOIR CAP.
i cleaned the filler hole with a clean towel , eye protection on and blew air PRESSURE into it with my mouth( lol refill) ,air , refill air some 10 times in a row . Every time I pulled my face away the system burped (not me) , level dropped
test drove car ,next day jusst added a little coolant to correct level no bubbles left it seems.
I dont like the bleeding screw on the tank (had two failing) wich is used engine running not driving screw slightely open cap closed .

 

During the headgasket test, I believe a lot of air has been thrown out of the engine.

It appears to be correctly working right now..

The temp rang is 93-99°, with no water going out by the water cap.

 

Why do I do it that way. Because the one mecanic that changed my oe jag thermostat housing and the coolant reservoir was not able too bleed the air out completely. 3 miles after leaving the shop, I had to stop and fill the freshly put in coolant with almost a quart of tap water out of a bottle .Contaminated had to change coolant again. And the new expansion tank bleeder screw was wrecked already .