I just completed a 2500 mile round trip journey in my series III XJ6 and noticed while driving the temp gauge never increased above 65 degrees. When I would stop for gas and restart the engine the temp would rise to 70-75 for a moment then within a minute or two it would go back to 65 and stay there until I stopped again and restarted. Just wondering if this is normal or not.

The drive was all interstate driving keeping it around 75 MPH.

 

Centigrade? A bit coldish to me. My lump runs at a consistent 90 to 100 C. It's LT1 designed to run on the hot side. For the 4.2, I'd say just shy of 90.


The guage markings in these cars sure is misleading...


Carl

 

Yes it is in centigrade.
I was thinking if it is indeed too cold maybe the thermostat is stuck in the cold position.

 

Yes, too cold and yes, likely a stuck thermostat

Jaguar used 82ēC and 88ēc thermostats in these cars.

Cheers
DD