mitsubishi spacegear 4m40 engine

has your vehicle got an electric cooling fan?

or is it a viscous fan the sort you can turn easily by hand when engine is not running ?

the fan is still the original fan.

Many possible reasons but if this problem has always been there; Make sure that the water pump impellor is on tight and the clearance between impellor and casing is as small as possible....it might be cavitating.

Please give all possible information!

Jurie sa

thanks for the advice sir/ma'am.

after cooling my overheated engine by dousing the radiator with water, i notice that the water/coolant tank is emptied!! for this, i have sealed possible holes in the coolant/water tank. in my own judgment, i hav thoroughly sealed the suspected leaks in the tank. its good though that i stop to cool off the engine when the temperature gauge hits 3/4. further, the power of the engine is still there. muffler smoke is still normal. however it still overheats. shall i replace the cylinder head gasket and the cylinderhead itself?

I know you say original fan is there but what type is it, fixed viscous or electric ?

If you are not losing power then from what little info you have given it would not appear to be head gasket.

I need more information.

fill header tank up when cool, the squeeze top hose as few times with header tank cap off.

reason on some motors the header tank doesn't fill the radiator directly, So you fill header tanks and think all is ok, but the radiator hasn't filled up, There are some Mercedes like this and they have a small plastic pug on the radiator top and this is where you fill radiator, replace plug then top up header tank.

Please answer

1 what type of fan.

2 is radiator core blocked with dust

3 is there any oil in the water " will look creamy"

4 is there any water in the oil " will look creamy"

Bad thermostat maybe?

Not familiar with that engine, but I had similar overheating problems in another vehicle. My overheating occurred during hard acceleration and sometimes randomly at idle! I suggested bad thermostat to the dealer and he thought I was daffy because he couldn't recreate the condition. I disassembled the cooling system myself and found the broken thermostat flopping around inside its housing. Several hours of (my) labor and a $5 part got me back on the road.

Yes i agree could be a stuck thermostat would cause overheating under load

my spacegear overheats during high speed.Have a new radiator.removed the thermostat and put silicone oil in the fan clutch.Still overheats at high speed.now oil is is leaking out of the cylinder head gasket.

remove the thermostat,put silicone oil in the fan clutch