The radiator was replaced, to my knowledge all hoses & piping, thermostat, waterpump,etc...The Jag is the Dr's across the street, he said he is going to give it 2 PBS,or NPR, but if I can come up with a remedy, He'll donate it to Moi. It's a Beauty,and I'll give it the TLC A Cat Deserves!!!
Thanks In Advance

 

How quickly does it overheat. Is it puking coolant out. Have you verified temp other than the gauge. Is the cooling fan coming on at the higher temp. Answers will help us to advise

 

You've asked a question yet given absolutely zero details. You said stuff has been replaced, but is that to fix a previous overheating problem, or is it still overheating?

Does it spray steam or coolant as it heats up, or even simply pump it out?

Does it lose coolant but not visibly? There is an underbody tray under the engine that can catch a lot of dripping coolant before it's enough to actually drip out onto the ground, so remove that panel when looking for leaks.

Did the water pump get replaced? If not, it may be weeping or flat-out leaking.

If it's overheating but you don't see coolant escaping, you may be losing it through the head gaskets due to head damage from previous overheat. Coolant escaping there could go out the exhaust, or drop into the oil pan. Is there water in the oil pan? Does the level of coolant in the recovery tank decrease?

Do NOT check that coolant level with it hot. System won't build pressure with the cap open. Make sure the level is correct while cold, then warm the engine up, and then wait for it to cool completely. Yeah, it takes a while, you're looking at checking it the day after warming it up!

Speaking of cap, is the cap holding the correct pressure? If it's weak, coolant will escape through the cap and disappear forever.

A complete cooling system overhaul is very involved. I did mine about a year ago after an obvious leak sprayed coolant and steam from somewhere I couldn't see. Took the car to a shop and had them pressure test, the found a crack in the radiator tank, quoted me an ungodly number to replace. I replaced it myself for a fraction of the cost, and ran into a series of next-weakest-piece failures: the recovery tank cracked, the water pump leaked, so I forklifted every component and hose, including one that goes under the intake manifold is is supremely difficult to access. See my thread here for a peek at what you might be in for, and that assumes you actually have no engine damage.