Toyota Repair: CAMRY OVERHEATING, radiator cap, temp gauge

Question
We have a 1993 Camry GX v6 Auto (UK model).
Radiator developed a crack in the head which resulted in overheating on a few occassions before we could get the cash for a replacement.  New rad fitted, but found it overheated on a normal run.  Driving at under 55mph kept her cool but when parking up can hear bubbling for a second or two so we are at the limit!  Mind you the temp gauge is rock solid just below half way when this is going on?  Chemical tests on the coolant indicate cylinder head is sound.  Apart from a bit which I guess steams off, she holds her water...?  This week took out thermostat to see if that was holding things up and ran without it - no change, except you can see the water circulating in the radiator now from cold.  We still have hot water, bubbling through coolant reservoir, and a rock solid temp gauge?  Did not want to spike her just in case I should damage the gasket.  Are we talking failing pump or something else - the radiator did not appear to heat evenly suggesting some sort of flow problem - or some other unexpected problem you may have come across. Any thoughts or past experience before we take her apart?


Answer
Sorry, but I'm a little bit confused, if the temperature gauge on the dash stays below the halfway mark what makes you think the engine is overheating? The only thing I can offer in this case is to replace the radiator cap,it may be weak causing the coolant to escape into the overflow bottle at a much lower pressure than it's supposed to.