unsolved over heating (Impossible to solve)

[lehiguy]

Did you use a Toyota head gasket or some after-market gasket? The one thing that you have only replaced once is the water pump itself. Could be the culprit. I would remove it and compare it to a TOYOTA pump. I remember going to my trusted parts guru years ago when the WP failed on my 60 and he pulled out the "correct" pump that looked nothing like what was on the rig. Off to the Toyota dealer I went. Same thing with head gaskets, some have the wrong sized holes in the wrong places.

 

[LCOwner]

Holes in the head gasket at the water jacket may be deteriorated and allowing too much flow. Wonder if you could find a warmer thermostat to compensate some.

 

[Elbert]

where over-heating issues can't be solved.... generally points to head-gasket, cracked block , cracked head... If you've run down every other issue (radiator, water pump, fan clutch, belts, fan blade, fan shroud, coolant mixture, timing, thermostat).

 

[morganism]

This is almost always a bubble in the thermo housing, that holds the thermostat. Park it on a steep hill, and run it for a while, to get the bubble out of the system. Or thread a bolt into the thermo housing so you can burp it on the flats after you change the thermo or pull a radiator hose.