Getting ready to replace my coolant hoses for my 99 xk8 and wanted to know about replacing the Thermostat Housing. How do I identify the Aluminum housing? Also I understand an aftermarket housing is available and wanted to know if anyone has used it. Is it worth the effort to look into? Also is it normal to see swelling of the hose between the housing & outlet pipe?

Thanks!

 

Gus,

I replaced a leaky housing with the aluminum one which was cheaper than the OEM plastic. The aftermarket one comes all shiny and bright. A couple of XKR owners have said that they had aluminum housings but I wasn't aware that Jaguar had used such at any time. If you question whether you have an aluminum one now, just scratch a little paint off in an unnoticeable place. The plastic ones are just painted also. Perhaps you might consider painting the new shiny one black to match the rest of the engine. There has been a lot of conversation on how to get to the bolts holding it on. The easiest way seems to be to just break the old housing into pieces since it is a throwaway. Cut slots in the short (rear) bolts to allow the use of a screwdriver to run them back down.

The little short piece of hose between the housing and outlet pipe all seem to be swollen.

The biggest issue I had was reconnecting the lower radiator hose to the radiator. It was a real bear to get on. I had bought OEM hoses but at that spot I sincerely questioned whether it was made large enough. Using the original spring clamp at that point was a real issue also. There is a tool made especially for installing a spring clamp in such a tight place but I gave up and used a screw type clamp.

 

I concur on the lower radiator hose clamp. Just use a screw type and don't both with the squeeze clamps.

Bent Wrench Trick

The two rear hold down bolts on the t-stat housing are indeed difficult to reach. Buy a cheap 8 mm box wrench. Heat and bend it 90" and use vice grips to turn it. The front two bolts may be accessed using a ¼” drive and swivel; but the rear two bolts have limited access.

Use Vice Grips

The bent-wrench should be used in conjunction with a needle nose vice grip, and another regular style vice grip twisting the first.

The box head end provides for a tight and secure grip on the 8mm bolts. Using the vice Grips, there is plenty of torque available to tighten the housing base down without fear of stripping the bolts or scraping your knuckles. Forget about the ground down sockets... this is the tool to use.

Shorter Bolts in Two Rear Holes

When replacing the new aluminum housing, use the old 8mm bolts that attach the T-Stat cover to the OEM plastic housing. They are a little shorter which allows for them to be inserted easier. I used needle nose pliers to first insert them in the rear holes.

Grind Screwdriver Slots in the Rear Bolts

It is simply too tight in there for you to get anything more than the tip of a finger on these bolts. Use a dremel or similar tool to cut cross slots in the heads of the two rear bolts. These slots will allow a screwdriver to turn down the bolts until they become snug. A screwdriver makes it easy. Then use the bent-wrench for final tightening.

 

I replaced my T-stat housing and hoses yesterday. It took about 2 ½ hrs to do the job. I did end up getting new clamps. The old ones were not compatible with the new thicker hose. I did end up bending an 8mm but that was a small price to pat to get the job done.

 

The swelling of the short hose is common but not normal. When replaced it will not be swollen and normail appearing.

 

I put a procedure on replacing the thermostat housing on my page. I want to thank everyone for the input and help.