So, i found my radiator bowed, and rotten, thats the old one out, now to beat the clock,before it's dark...

 

New thermostat in, Guess what, there wasn't one in it!

 

Ha,

Yeah I had that, no thermostat, in an XJ6 I had years ago. It ran much better with a thermostat installed so the engine could run at the correct temperature.

Maybe the PO took the thermostat out because the radiator was dodgy.

Cheers,
Jeff