Jon, Sorry, I was thinking of the whole tower that is on the 4.0, a right pain. Yes the thermostat is a easy out, if that is all you will replace. I could do that without breaking something (maybe).


Wayne

 

No worries, Wayne. I would always rather have too much information than not enough....

Thanks for the easy bolt access confirmation, Dennis....

Now if I can just locate that cover/thermostat/seal kit tomorrow morning, maybe I can fix this damn thing over Thanksgiving weekend and get my wife off my back about having to drive my lowly S-Type around instead of her beloved XK8....

 

Jon, Let me add one little thing about the bolts in that thermostat housing. They are being installed in a sleeve in the plastic and as that is old, any over torque will lead to a complete replacement, be careful.


Wayne

 

Thanks for the tip, Wayne. You know me - with my gorilla hands I have a tendency to over-tighten everything. I'll remember to treat these bolts with kid gloves....

Guys, any additional tips and tricks to doing this job properly would be much appreciated. I've never had to do thermostat housing work before so I'm learning on the fly....

 

Jon-

You should replace the whole plastic outlet pipe assembly, not just the cover and thermostat. The whole assembly is made of the same plastic and and the older bits will also crack and leak soon also. Replace it all and just do the job once and more importantly lessen the chance of a failure on the road. It is really not that much more for the whole assembly which includes the thermostat, thermostat cover, outlet pipe and coolant temperature sensor.

 

Steve,

Thanks for your input. I hear what you're saying. I continue to wonder about any plastic component in both of our Jaguar engine bays. But my understanding is that the entire thermostat assembly was much-improved for the 4.2 engine compared to the 4.0 engine. Is that not true?

 

OK Jon, you just got the word from the main most man. Now it's turned into a job.
Oh, and I do agree with him, not much further to go and no call from Jan in Savanna setting in a tow truck.
I think someone just did this on the later model, will look for the thread.


Wayne

 

It was improved, but certainly not to the point where it lasts the life of the vehicle. My 2003 4.2 (S-type) coolant pipe had hairline fracture leaks at about 8 years of age and judging from other posts it is a common problem.

The whole assembly is under a single part number BTW. I think the dealers are encouraged to replace the assembly.

 

Jon, Found it right away, should help ease your mind.


https://www.jaguarforums.com/forum/x...estion-130426/


Wayne

 

Jon,

Still can't figure out where my paperwork went on this job. Maybe I misfiled it in the "01" folder, which went with the car when I sold it.

My indie tells me the plastic bits on the 03+ cars hold up better than those on the earlier cars. Different plastic, if I remember right. That's all I know about it.

See pgs. 6 & 7 of the attached terrific reference on the '03+ cars. Talks about the thermostat job. Come to think, seems I recall it talks about the different plastics somewhere too, but can't remember where.

 

Thanks to all for the additional feedback. As much as I dread tackling it, I am now considering replacing the entire assembly (as recommended by Steve and Brutal) rather than going with just the cover/thermostat/seal kit that Dennis used. I agree with the concept of only having to go in there once and minimizing the chances that my wife gets stranded halfway between Raleigh and Tampa due to a leaking plastic thermostat housing assembly part....

Anyone have a part number for the entire assembly that Steve is talking about?

Where are these infamous rear bolts that everyone has to find different ways to battle? Are they visible and obvious only after you remove the thermostat cover from the housing? And what special tools are needed? My current tool array is limited and with my huge hands, I have great difficulty getting to bolts and screws in tight spots....

 

This is a link to my 99xk8 that not the same as yours but the rear bolts for the housing I think are the same. You can see how I did mine. I hope it helps!

Link JagRepair.com - Jaguar Repair Information Resource

 

Thanks Gus. Those two rear 8mm bolts look scary in the 4.0 engine. I wonder if I will face the same problem in our 4.2 engine. The entire assembly is shaped quite a bit differently from what I can tell but I have no way of knowing what to expect. I hope others with 4.2 engine experience will chime in and educate me. As I said earlier, I have no experience in this particular arena so I'm learning on the fly....

 

I think it is a pretty staightforward job on the 4.2.

 

Jon, I think that a 1/4 inch drive, 8 inch extension and a universal, with short sockets will keep you from over tightening and allow you to get all the bolts. The cover off the front of the intake is something the 4.0 doesn't have, just get the gasket.
I know it's a small leak, but it could be a major one half way here, because you know I would be glad to help.


Wayne

 

I need to look at one.

 

OK, if Gus is coming to help, I'll be there!!!!!


Wayne


(LOL, Had you worried Gus)

 

Wayne,

I wish I could drive it to Spencer for both of us to tackle but there's no way the car is going anywhere right now. I think the pressure test this morning not only exposed the leak, it also made it worse. I doubt the car could make it more than 10 or 20 miles from home now without emptying the coolant expansion tank as a result....

In the thread from Stamford that you attached in post #29, he states that he had to use a bent 8mm wrench held in vice grips to get the rear bolts out. So I'm not certain if just a universal on a 1/4 inch drive with an 8mm socket will get the job done, especially if I cannot get my fingers in there....

 

Jon, my thoughts exactly. I know you can handle this, after what I have seen you do. Your biggest issue, is the antifreeze and you don't have a big tray, maybe line a large cardboard box with aluminum, folding over the edges to get a seal when you have to use a couple of sheets. You will only lose it down to the bottom of the housing, so a couple of quarts at best.


Wayne

 

Wayne,

Your custom-made crow-foot wrenches are looking better all the time. I'll gladly reimburse you for all shipping costs if you'll send them to me....