For the third time since I bought my '99 XJ8, I have a major coolant leak. This one I have been unable to trace by looking from the top of the engine. The leak appears to be at the rear of the engine block on the right hand side. When I look underneath the car the coolant appears to be dripping off the leading edge of the transmission (although it could just be gravity taking it that way - the driveway is slightly inclined). At present I don't have ramps or jack stands to get a closer look. What do I need to be looking for?

 

A common source of leaks is the Norma connector at the rear of the engine connecting to the heater hose. It is a permanent part of heater hose and the entire thing has to be replaced to fix it . . . if that is where it is leaking. Best solution to find a coolant leak is to rent/borrow a pressure testing system from one of the auto parts stores.

 

The LH Norma connector has an o-ring which can be replaced.
For the RH connector, I cut it off and spliced in heater hose.

 

is it an octopus? Cuz i've seen one...once. Thought it was a myth, but sadly no.

 

first thing that went wrong on my 2005 XJ8 super was the radiator leak from one of these bad designed clamps. I should change them all honestly and soon.

 

My local Jag parts guy calls it the "medusa hose", though it goes by other names given its location.

 

that's a good one, and so appropriate

 

I haven't gotten far enough in to see the hose. I read the replacement procedure on another Jag board and heard that it involves pulling the intake manifold and throttle body, plus disconnecting the fuel feeds from all the fuel injectors.

My leak is on the right side. If I isolate it to the connector, I may well do the same thing rather than tear everything apart.

 

It is possible to replace the RH heater hose by pulling it under the intake manifold attached to the old hose.

 

You need to replaced both the heater hoses under the intake and the heater hose matrix(medusa, octopus etc)
you only need to lift the intake and it will pivot on the 2 bolts under the throttle body in each side of the intake. If you do the heater matrix assemlby just remove the throttle body. Any way unclip the electrical connectors from the injector and pull up out of the way. Take out all the 10mm bolts holding the intake down and the air intake tube from the air cleaner to the tb. Then you can pivot the whole intake assembly up from the front and slide your arms up under the intake to change the heater hoses...you may also want to order a part load brether cause youre gonna likely break it

 

Thanks for the tip. I'm inclined to replace all that stuff, since any kind of patch job is likely to be only a temporary fix followed by a leak somewhere else.

I've seen photos of the hoses under the intake manifold. Where is the so-called "medusa" hose located? You mentioned removing the throttle body.

 

It goes from the botoom of the coolant reservoir to the heater control valve, below the throttle ontop of the trans bell housing along to the heater hose metal pipe on the passenger side. Theres also a tie strap hidden above the trans you need to cut off to get the old 1 out. And cut the old 1 in half to speed removal