I just bought the whole combination piece because my thermostat was failing, any tips before I take on this job? It came with the gaskets and I have permatex to put down before I reconnect everything. Is there anything I should be aware of? I've never tackled a job like this so any input before I tear it all apart is appreciated. Picture of the part for reference.

 

Wasn't there an upgraded metal version available? Or am I thinking of something else?

Did you purchase part #AJ811793? That's what I saw listed at RockAuto. When I searched by that part number, I came across this thread that may be of some interest:

https://www.jaguarforums.com/forum/x...93-tips-114486


Before installing the new thermostat, I HIGHLY recommend testing it in a pot of water on your stove. I've had several bad from stock on various vehicles in recent years. OEM, quality aftermarket, white box, it didn't matter. Save yourself some aggravation and test the new one before installation to be sure. NAPA has a good guide with more details:

https://knowhow.napaonline.com/tempe...ps-and-tricks/

In a nutshell, the thermostat should start to open at the rated temperature, +/- 3 degrees F, and be fully open within 20 degrees above that.

 

The four Torx screws holding the lower section to the block can be difficult to remove with the inlet manifold in situ. The screw heads can also be easily stripped if the tool isn't completely seated straight.

There is no need for any gasket sealer since the o-rings are being replaced with the assembly.