Weird problem, bet somebody here has seen it happen. Replaced water pump, fan clutch, thermostat (gray LR 180 original), reservoir cap (Atlantic British) about 2 months ago. Bled, re-bled, extra bled until niagara falls could not be heard behind dash. Being serious, bled like RAVE says. As soon as vehicle is started (even early morning startup) I can see coolant forced downward below fill line, but no sign of coolant leak. If I were to slowly release the built-up pressure, and then carefully remove cap, coolant returns to its correct fill level. I had actually seen this happen in another discovery, but it wasn't mine, and I can't contact that owner to ask if he ever got it fixed. Feeling like changing head gaskets, but not sure if depleting my checking account will cure my rover.

 

Oh, temperatures increase to about 230 on idle traffic light stop(especially if AC is on), and then go back down to around 206 at highway speeds, never overheated as far as dash temp gauge, never any coolant/steam overflowing and needless to say, rover is deadlined (not to be used) until fixed in order to avoid head warpage.

 

230 is very high at idle, first things first, does your electric cooling fan come on at around 211 with the ac off?

 

No, it will not come on on its own, unless I hit its motor with a hammer.

 

I wouldn't worry about the coolant level as long as its close to the level line it should not be your issue. Are you loosing coolant? First would be to sort out the electric cooling fan. Next even with the fan fixed it sounds like your highway speed temps are still high with the gray thermostat. Therefore I would take a look at the radiator and condenser, make sure the fins on them are clean of debris. If they are, it might be time for a new radiator. Sort out the electric fan and report back on operating temps at long idle and highway speeds. How are you reading the temps?

 

Temp readings through obd2 scanner, radiator and condenser were inspected, found to be clean, still I washed them out with garden hose, same temps. The reason I'm worrying about coolant level is that it will get as low as to barely be seen at very bottom of reservoir bottle, no circulation visible

 

is you belt routed correctly

 

Yes, belt verified to be routed correctly.

 

Beginning to suspect realization of worst case scenario... Head gasket failure of impending doom... Impended.

 

Strange symptom, have you tried a pressure test? No white smoke, mayo in oil or on oil dipstick or bottom of oil cap?