Originally Posted by
NissanGQ4.2
This is from my old man Andy, I asked him to have a look at your post
Our fans do not have a nut holding the fan blade onto the shaft. They are pressed on and there is a wave type clip on the end of the shaft. Some models (I think they were called a pancake design, motor was very thing) did have a nut as the fan blade itself had to be reversed to change the air flow as the motor would only run in one direction. Our fans have the fixed fan blade as the motor direction is reversible by swapping the wires over.
These fans should be able to run all the time with out any problems.
He stated that the water temperature gauge is 3/4 but that does not give any indication what the actual temperature is.
Over heating can also be caused by the bottom radiator hose sucking closed (clasping in on itself). Some vehicles have to have a spring wire coil inside the hose to stop them clasping in on them-self. This is usually cased by high draw (flow) caused by a water pump that is trying to move a lot of water into the motor.
Is he using a water thermostat in the engine. If removed it can cause overheating.
There is a lot of things that can cause over heating is wrong size fans, no fan shrouds to direct air flow, fans set too low on the radiator, air not being directed onto the radiator (that is oncoming air hitting the front of the radiator and being forced under or around the sides) Ignition timing, fuel mixture too lean at high speed .
As in another post the fans could be turning in the wrong direction and the wind pressure is putting a lot of strain on the blades but that should not cause them to melt, but may cause twisting on the shaft nut or clip.
There would have to be a massive of heat on these fan blades to cause any damage to them that is unless there is a fault with the materiel that the fan blades have been made of.