Thanks Ben, yes ur absolutely right, water.
I had just removed the stats to test if the overheating gets better without them, but prior to testing the car, I read all the info above.
I had filled up the water that came out with normal water as I knew I will drain it out again and reinstall the correct thermostats, so didnt want to waste any antifreeze.
I had not even run the engine when I reopened the housing to see the circulating pipe's opening inside the housing, hence ur observation is spot on.

Thanks for the comments on vacuum, will take it up in another post if not answered here.

Cheers

 

Thanks for your comments and for the write up attachment.
OK will check things out again once the thermostats are installed, but I must admit I was surprised with the temperatures recorded as none of my other (non Jaguar) classic cars go that high under normal operation.

Will see
Cheers

 

Thanks again for the writeup on vacuum lines. Much appreciated and I am sure I will learn a thing or two from it.

Cheers

 

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They would of you lived in Kansas !