XJS 92, V12 5.3, Facelift
Hi again, tried to search for this topic everywhere, in the book, in the cooling guide, but no big luck.

So, this heater valve located in the worst place i could imagine, is it even possible to replace it without removing too many things?

Seems like if i buy a long socket wrench i can get to the bolts through the wiring, but not sure

In the book they also say its a pain to remove it and advising to bypass it by installing heater valve on the side and connect it to the old one, but dont wanna do that kind of a mess

 

No idea what model year and engine you have.

It's not a problem on the facelifted six cylinder engines.

 

Sorry, its XJS 92, V12 5.3, Facelift

 

It's not that hard to get to. Just remove the large crossover pipe between the two inlet manifolds at the back of the engine, and the heater valve is easy to get to then.

 

Replace the 3 heater hoses at the same time.

I dont try and twist the hoses from the spigots, I simply slice the hoses along the length, and peel away.

Damage to the firewall spigots is too easy to do, and will 100% increase the Bad words you speak.

New clamps and PAY ATTENTION to orientation of those clamps, as you WILL need to get at them after a couple of hours running to tighten them. If "the angle of the dangle" is not right you cannot tighten them, so a coolant leak will be your best friend, as will the above Bad words.

 

Good advice, and also use clamps with hex head screws.
Flat head screwdrivers slip out of slots if you don't have a straight shot.

 

IIRC, this is the valve where, when I was doing my coolant hose R&R, I came to the conclusion that Jaguar used specially trained Rhesus Monkeys to install the valve. They are the only creature with the small hands required.

I have another hose job coming up, I'll probably just put a new valve in as a way of PM so I only have to do it once...

 

ok, thanks everyone, finally did it, took me about 3 hours to replace valve and all 3 hoses around, i actually couldn't believe its possible to put new lower heater hose back=)

btw new hose touching valve cover and header a bit, is that ok?

 

Valve cover, ok
Exhaust header, NO

Paul