My poor old 1995 XJ6 needs new plumbing. Especially after the hose from the rear part of the cylinder head to the heater control valve fell apart. So I am in the process of collecting hoses. The information I need from this group is info on some of the routing and access problems. There is a small hose that goes from the thermostat housing rearward that I cannot figure out where it connects to. And the large water pump hose that goes rearward and connects under the intake manifold. Is this one that is impossible to replace without removing the intake manifold?

Info regarding both of these hose along with any other tips would be appreciated. And if some one knows where I can find a complete diagram of the hose system that would be a big help.

Thanks guys.

 

I didn't replace the heater hoses yet, but I did the octopus and the hose under the intake to the pump. The hose out of the back of the thermostat housing is part of the octopus. The only thing I removed for access was the air pump.
The octopus is a uro, and has held up for a year so far, but they do seem to have a bad reputation. Just recently I had to tighten a couple of hose clamps, but no other problems.
There was a lot of pitting and oxide buildup on the aluminum castings and cleaning them was a pain.

 

Like this one?



It's in the downloadable service manual, in one of the stickies at the top of X300 section :P

 

Bypass hose - I changed it without disturbing the intake manifold. Also removed the air pump for access. You may say I "cheated" in that I had the hood (bonnet) removed to facilitate other maintenance. This greatly improved access!

Maybe a few of these pics will be helpful:

https://www.jaguarforums.com/forum/x...enewal-101914/

 

The water rail hose (aka MF hose or BA$T&*D hose) can be replaced with the intake intact but access is difficult.

bob gauff

 

What a great response. Thanks guys. Your info is greatly appreciated. This info will certainly make the job easier.

Thanks again.

Bob

 

Give yourself an early Christmas gift and have someone do it. The "octopus" hose, at least on the XJR, is an 10 hour job.

 

If you are going to change all the hoses, then I would opt to take off the manifold. Not just to improve access to the bypass hose which is fiddly otherwise, but also to go ahead and remove/clean the water pipe and put on new gaskets. This is often an area that leaks.

You don't have to take the manifold out of the engine bay, just tie it back. It will make the job a lot easier and you can go ahead and clean the throttle body, EGR valve et al while they are out. Do it right and you'll be set for the next 10-15 years

 

I forgot to mention: pin the hood in service position.

 

Here is what I have found so far in my research and much use of a flash light and mirror. There are several differences in my car and the diagram. I am attempting to either modify the diagram or make a new one that matches my car. And, the small hose that leaves a coupling at the back of the thermostat and goes back under the fuel rail is not part of the octopus thing. It goes to a fitting on top of the intake manifold behind the EGR valve that is also connected to the cam cover breather hose and another hose that goes down under and connects to another fitting (?). At least I can replace that one without messing with the octpous.

Stay tuned for more info and soon maybe a new diagram. It seems to me that this horrible mess could be greatly simplified and a much better cheaper system rigged.

 

You must mean this one that I didn't take a pic of:

an excerpt buried deep in this thread:
https://www.jaguarforums.com/forum/x...enewal-101914/

"I decided the only sure way to clean it off and insure a good seal on the new hose was to remove the t-stat housing. So off with the wire connectors: (I left the small hose that goes to the overflow bottle on as it was already detached from the overflow previously. However, you must remove the same-size hose that is mounted to a nipple adjacent to that one that points to the rear - sorry, forgot to snap a pic, but you can see the nipple just aft of the clamp on the small hose)"




Sorry, I didn't change it, so didn't care where the other end went, just took care to get the forward end attached to the proper nipple when I put it back together.

I did manage a pic on reassembly, but guess it doesn't show you what you need - maybe someone else will recognize what it is called:

 

I found the same build of of nasty. I used a paint can opener, and it scraped away the crud with ease. I was able to hook the loop on my thumb with the limited access and clean it well.



Followed up with some 80-grit emery cloth.

 

No, that is not the fitting I referred to. That is the thermostat housing. In your second picture the small hose that goes streight back goes under the intake manifold and connects to the fitting that I am referring to. You can see the fitting under the fuel rail cover just behind the EGR valve. The hose from the thermostat housing connects to it as well as athe hose to the cam cover breather hose and there is an electrical connection to it as well. What is that thing? Water and breather air at a common fitting is strange.