I just looked at Grant Francis' pinned PDF at the top of the forum and I think what I have here is a failure in a water tube he has listed under item 11A; it appears to run the length of the engine, front-to-back, and it's dripping from what appears to be a very disintegrated seal right over a heat shield over what I'm guessing is either the cylinder head itself or the exhaust manifold.

I'm attaching a picture but I had to wedge my phone down into a small gap to get a shot of this, so if the angle looks wonky to you, sorry as it couldn't be helped.

My biggest question is where do I get replacement parts for this and what is it called, when I go looking for it. Thanks in advance:

 

Water transfer tube, ONE on top of each head.

C42595 Water Tube
C37990 Tube Seal, 2 per tube, one each end.
C30344 Gasket, 2 per alloy housing.
Edit removed, that C30344 is the coirrect Part Number.

Front OR rear housing will need to be removed to do this.

BUT BUT

The bolts that hold those housings to the cyl head, are well known to break, Metric 8 from memory, so be prepared for extra time, and beer, to do this.

THEN

Look at the housings, where the tube was, and inspect the seal orifice, they corrode, and I used Black RTV, to seal them, AFTER I cleaned all the crud out. There may be more fancier sealants these days, dunno.

This a time consuming task, and there are NO shortcuts.
Last one I did, 20 years ago, took 2 days, and broke 4 bolts.

Suppliers, SNG, David Manners, etc. Members in your market will have suggestions.

 

If a bolt breaks, in spite of your being very careful, then it can be drilled out. If when this happens they key is to flatten off the broken end in the head and then punch it very carefully in the middle of the flattde off broekn end.
Then using a LEFT HAND (ie anti clockwise) good quality HSS drill bit, slowly drill out the bolt. It does not matter if the threads in the head get messed up, you can retap to a slightly bigger size.

 

Greg is spot on.

I suggest removing the Front casting, as the room at the back to get a drill etc in is tight at best.

 

Had to remove all 4 housings on my car. . I used lots of penatrating oil and an impact wrench. Idea behid impact wrench is that the short bursts of large torque are bettter then trying continues torque . Basically the bolt doesn;t have time to break Maybe i wasl lucky, but i didn''t break any of the bolts using this method.
Oh, ,and i replcaed with copper pipe i.i.o steel water pipe (diameter used is some standard aircon diameter). No more rust here and looks nice

 

G'day Jess,

All good advice above.

I have a 1995 6ltr V12 X305 and the coolant tubes on it are a lot shorter that those on your XJS and when I replaced mine I used the standard seals and I sourced some stainless steel tube of the correct diameter from a hardware store and they have been leak and rust free for over 15 years now. I believe the OEM pipes are galvanised steel.

Cheers,
Jeff.