FYI - I recently had a new thermostat installed due to overheating issues on my 2003 STR with 80k miles (now resolved). The mechanic said Jaguar issued a TSB on original thermostat and that if you get a new one it now uses a different parts number than before. Just repeating what I've been told, take it for what its worth.

 

I have not heard of this TSB?

Can you post a copy or at least the number of the TSB?
Would be a help to the rest of us.
.
.
.

 

My mechanic showed me some document stating there was a TSB but I do not have it. All I have is the receipt from my work done. That, and this hearsay information. Sorry I can not be of any more help. He said the new parts number model cools the engine 20 degrees cooler - I do not know if he meant as compared to the original or compared to my overheating car. I wish I asked more questions for your guys but it was raining and I just wanted to get home so I did not do much more discovery.