Outer Limits 4x4 Board

Hi...

Just thought as some of you live in way-hotter climes than us, I'd seek an opinion or more on a problem that has us puzzled.....

My father has an '87 2.5D 110 (N/A) with 90.000 kms on clock; it recently began to gradually run hotter & hotter even on cold days in spite of a new radiator (fitted for different reason) less than a year ago.

Only the top l/h corner of the rad gets hot ....engine goes into the red, but yet with the thermostat removed......it does'nt even really get warm enough to raise the needle, rad gets warm-to-cool evenly across & water flow is fine.

A new thermostat was fitted......same problem arose....so it was'nt that..!

Just occasionally it does'nt overheat at all or runs just out of the white sector.....

Squeezed all hoses for airlocks, no water in oil & no oil in water, so guess it cant be a head gasket...

Heater works (as you'd expect when the heads so damn hot...!!) too...

Flat out with shearing at present so further investigations may have to wait a week or two...

If the rad is not getting hot, it is the t. stat or the water pump.

Just because the t. stat is new, do not rule it out, they can come crap from the factory. Is it in the correct way? In any case, pull it out and TEST it. Put it in a pot of water and heat to boiling. Check that it fully opens. If you have a thermometer, check at what temperature it opens.

Make sure the event line from the rad to the coolant resevoir is clear as that is what lets air out of the system.

The engine should be impossible to overheat under any circumstances. the rad is WAY oversized for the engine.