Quick question … anyone know what temperature thermostat originally came in my 1989 XJ40 ?
I’m almost sure that mine is stuck open. Engine is very-y slow to come up to temperature and never really gets there in this cold Texas weather.
I believe the factory EBC3621 stat is an 88 degree C, or 190 degree F thermostat. Bit of a choice available at Rockauto, temps and brands. I like Stant myself, but the Stant they have is a bit on the c-c-cold side for me.
https://www.rockauto.com/en/catalog/jaguar,1989,xj6,3.6l+l6,1178221,cooling+system,thermostat,2200
Thanks Larry …
Since my super cool digital temperature gauge has 90c as the middle reading a 190F degree thermostat only makes sense. Already ordered. By the way I love Rock Auto !
Whats not to like (exclamation point)
They are based in the US, a bit of a hike for anybody either side of the ponds 
Well I FINALLY got my thermostat problem sorted out …
… but not without some bumps along the way !
New thermostat didn’t work. I put the old thermostat and the new one in a pan of water that I heated up. Guess what, the old thermostat worked fine but the new on never opened up, even when the water boiled.
So I purchased another new thermostat and it tested fine. the old one was a 187deg unit and the new one is 192deg. Hopefully this would give me better heater performance.
Then the thermostat housing broke when I was bolting it back on. Give me a “break” (drum roll and cymbal crash please) !
Ordered a new housing and put everything back together and success. The temp now sits one bar to the left of center, 90c mark on my (very cool) digital gauge and the heater performance is much improved.
Bad break cracking the housing. 
Oh well, new one on so all good now …still, not what you want to happen when you swap out a simple part …
Even worse when you are on a charity rally and it cracks going up a hill, luckily I noticed the temp climbing so no damage done (the car cost $nz700.00) managed to find one in Nelson (South Island) I organised a replacement for the one I acquired ($150.00 ouch)
Robin …
$150 NZ that’s what, like $103 US. I paid $71 for my brand new one from Engel Imports and I thought that was rude (several used ones were available online for around $30). But being in NZ I think car parts prices must be a lot like buying real estate … location, location, location.
By the way, “The World of Wearable Art & Collectable Cars Museum” … now what’s that all about ?
Very strange dresses and a car museum, satisfies both genders. Went through last month;
Only a small line up of Jags;
The Mini is the <1000cc record holder that went to Boneville a few years ago and featured in a Jay Lenos’ garage;
Looks like the ass end of an Isetta bubblecar in the foreground?
Yep quite an eclectic mix of cars.