Engine cooling system diagram
The engine cooling system works according to the following algorithm. Until the engine is warm, the coolant (coolant) is pumped by a constantly running water pump only in the head and cylinder block, as well as in the interior heater heat exchanger. When the coolant temperature rises to a certain level, the thermostat opens a large cooling circuit and the coolant circulates additionally through the radiator, being cooled by the air passing through it. When the coolant temperature reaches an even higher value, the electric cooling fan turns on, which creates additional air flow through the radiator fins to more intensively remove heat from it. The water pump is driven by a belt from the crankshaft.
Before working in the engine compartment, especially in the radiator fan area, be sure to disconnect the negative cable from the battery and the fan wiring connector, because. it may turn on due to the effect of heat conduction even when the ignition is off.
Do not open the cap of the coolant expansion tank or radiator until the engine has completely cooled down to avoid burns from hot liquid or its vapor.
If necessary, open the cap of the expansion tank when the engine is hot, wrap it with rags. Remove the lid slowly, gradually reducing the steam pressure.
A description of checking and adjusting the coolant level, replacing the coolant, as well as some checks of the cooling system are given in Sections Checking fluid levels, leak control, Checking the condition and replacing hoses and tubes in the engine compartment, localizing leaks and Coolant replacement.