Typical malfunctions of the cooling system are leaks and insufficient cooling efficiency of the engine. The first is due to damage to the hoses and their connections, the liquid pump seal, damage to the gaskets, cracks, and the second is due to a fan failure, water pump failures, malfunction of the thermostat, internal and external contamination of the radiator as a result of scale formation.
Signs of a malfunction in the cooling system are engine overheating and boiling of coolant in the radiator, if they are not the result of a long and heavy engine load or improper adjustment of the ignition or power system.
Thermostat Troubleshooting Algorithm
Attention: An indicator stick is similar to a regular stick and contains a material with certain chemical additives that provide a given melting point. By applying a pencil bag at 88°C and 100°C to the thermostat housing, you can check the thermostat's response temperature. These bags should melt when the coolant reaches 88°C and 100°C respectively. These temperatures determine the operating range of the thermostat. Therefore, if circulation does not occur, then this means that the thermostat may be faulty.