Defects of Water Cooling Systems
Channel: Study with shivam sir 
Date: 03/06/2021

Overheating of Coolant Defects

This is caused due to rusting or sealing of water jackets and radiator.
The other reasons are defective hose, defective water pump, a defective thermostat, slipping of fan belt, blocking of the air passage in the radiator and loss of cooling water.
The heat transfer from the wall of the cylinder to the coolant is mostly affected due to rusting and scaling takes place on the walls.
This may be removed by washing the cavities with ordinary washing soda or some other chemical and reverse flushing.
Sometimes worn out hose material goes into the water passage and accumulates there restricting the flow of coolant also.

Replace the defective hose at earliest.
Repair defective water pump and replace the defective thermostat. This will solve the problem.
The circulation of air is effected by slipping of the fan belt.
Hence tightened the fan belt as per requirement or replace if required to remove the defect.
Also, Remove the greasy material if found on pulley grooves.
Clean the radiator by blowing air under pressure from fan side.
Water must be filled in radiator up to a required level to recover a loss of coolant.

Overcooling Of Coolant Defects

Over Cooling is generally caused by a thermostat that opens too early or remains open at all times.
In some cases, it is observed that there is no thermostat employed or missing.
If By-Pass valve remains open at all time, it results in the overcooling of water.
Hence to avoid overcooling, the defective thermostat must be replaced.
An early action should be taken to close the By-Pass valve.
The circulation of water may be affected due to the freezing of cooling water as it blocks the circulation passage.
To overcome this problem, the engine must be run idle for some time until it attains the proper temperature.