Question : I HAVE done a top overhaul after the gasket of my Perodua Kancil 850 (manual, year 2000) burned out due to insufficient water.
Since then, my car is having an overheating problem.
I have changed the water pump and radiator. I have also included a thermostat.
I am still facing the overheating problem and it gets worse when the air conditioner is on.
Is it advisable to have the thermostat?
Usually, when there is an overheating problem the cylinder head will become warped (i.e. no longer flat).
In that case, the workshop will usually send the head for skimming where a small amount of material is removed from the surface of the head to make it flat again.
Sometimes too much is taken off the head and this results in the compression ratio going too high and the engine starting to "knock".
The workshop will then retard the ignition to stop the "knocking" but this will result in overheating.
Another cause of the overheating could be that there is a hairline crack
in one of the combustion chambers which when heated allows the heat of combustion to get into the water jacket and the temperature will go up, usually followed by loss of coolant.
My suspicion is that you have a problem with the cylinder head and this will have to be checked out.