From what I have read it seems that my 1993 XJS 4.0 six cylinder should get a 180 degree thermostat for a replacement. Is that correct? Also, I've noticed that Jaguar mechanics are picky about what brands are best to use, so is there a specific brand I should buy as well? Thanks!

 

93xjs6cyl,

I agree that you should buy a good quality 'stat for these cars. Just buy it from Jaguar - EBC3621

Paul

 

I couldn't ascertain the current manufacturer for Jaguar's thermostat, so I bought a brand that I liked.

The original thermostat that came out of my 96 was made by Waxstat. It seemed pretty beefy and well made. I don't believe they exist anymore.

I ended up with a Meyle thermostat. It is the OEM manufacturer for Mercedes Benz thermostats. Cost me less than $25.

Make sure you order the gasket as well, part NBB2217AC.

 

I also wanted to replace the stat in my '96 4.0 but found the bolts so tight after 18 years that I was afraid of breaking them. I am waiting until I have to do it.
Cowardly?
RagJag

 

Thanks! for your replies. RagJag, not cowardly...actually thoughtful. You might start spraying the bolts with a penetrating catalyst (rust buster) and see if that helps. I will do some research on those part numbers and see what I will find.

 

Penetrating oil overnight with some induced vibrations, heat, whacking into the head of the bolt (along its axis) are all techniques to break it loose. I go in that order, depending on accessibility and proximity. Also use a 6 point socket, not 12 pt, and try tightening slightly ( till the seal breaks) before loosening

 

I had a similar problem on my x308. I'm sure it's also partly caused by steel bolts in alloy housings. One thing that I did was to run the car up to temperature, then carefully release all the pressure by carefully releasing cap off header tank. Then replace cap (in case it helps to stop air entering and more coolant escaping via stat housing) than managed to undo stat housing nuts. It seemed that the heat expansion helped.

Paul