My 97 decided to start overheating today, 65f outside, I know the pump has been changed fron the plastic awhile ago. Fluid is full and will idle without overheating. How can I check if its the thermostat?

Don't take any risks over heating a Jaguar V8. It's an engine killer.

The thermostat has to come out to check it opens at the right temperature or even opens at all. Heat it in a pan of water and check with a thermometer for the temperature at which it opens.



I like this technique for two reasons:

1. it's simple
2. it drives my wife to distraction when I do vehicle maintenance in the kitchen

Graham

thanks, but I meant diagnose in vehicle.

As a bonus, it gives you another use for those feeler gauges hiding in the bottom of your toolbox.