stefan P (Penrith NSW) replied:

sounds like blocked radiator....get it rodded

cheers Stefan

Martyn (WA) replied:

Nigilor,
You would expect the bottom to be cooler than the top this proves the radiator is doing it's job. But as mentioned above if the temperature is significantly different then you are probably looking at a blocked radiator. Chemical cleaning is one option, getting the core cleaned by a professional is another this includes removing the header tanks, on older radiators this can lead to problems in the future they never seem to seal as well second time round. Other option is a new or reconditioned rad. Would be interesting to see know how blocked it is, just enough it appears........

Member - Kiwi Kia replied:

Do you know any one that may have an infrared temperature gun ? You just point it at the spot you want to know the temperature and get a digital readout. If you can get hold of one of these you can do a sweep up and down the radiator and see if some areas are warmer then others. This could indentify any blocked tubes. Saves pulling the radiator to bits and 'rodding' it if it's not needed. As has already been sugested are you 100% convinced that the viscous fan is working properly ? That would be my first bet.

tuffygordon replied:

Cheapest option is to remove the thermostat and test it.Put thermostat in boiling water and it should open up.

Dave Thomson replied:

Had an overheating prob' once with my Hilux cut a long story it turned out the clearance on the bottom tank is too small so had it extended {cost $100.00} and solved the problem after elimanating all the usuals , thermostat etc,
regards,
Dave

nigilor6 replied:

well i checked the thermostat and it says it opens at 88 degreebut when i boiled up the water it was closer to boiling point so hopefully it is just a dodgy thermostat, when i drove the car around to give it a flush without the thermostat in it the temp gauge stayed lower than normal so hopefully im on a winner here