Engine - Engine and crankcase
Cooling system
The function of the water pump mounted at the front of the engine, is to maintain a continuous flow of water around the
cooling system. This is essential to ensure correct engine temperature, and performance, during vehicle operation.
The pump is driven by a ‘V’ belt from the crankshaft pulley, when the engine is running.
The cooling system for the new generation of engines, is of recirculating by-pass type with full length water-jackets
for the bottom tank of the radiator by the water pump, which passes the coolant to the cylinder block. This coolant
then flows through cored passages to cool the cylinder walls.
Passages in the cylinder head gasket allow coolant to flow from the cylinder block, into the cylinder head cored pas-
sages also conduct the coolant to the fuel injector nozzle locations before re-entering the water pump below the
thermostat.
The thermostat is located in the top of the water pump body, and controls the flow of the water as required by tem-
perature changes.
NOTE:
A faulty thermostat may cause the engine to operate at too high (hot) or low (cold) on operating temperature.
If not replaced this could result in a damaged engine or impaired engine performance.
When the thermostat is closed a recirculating by-pass is provided to allow the coolant to recirculate from the head to
the block to effort a faster warm-up.
Once the engine has reached its normal operating temperature, the thermostat will open and allow water to be drawn
through the radiator by the pump action. Cooled water then returns to the engine system. Cooling occurs as the
coolant passes down through the radiator cores, which are exposed to the air as it is drawn through the radiator by
the fan.
NOTE:
Do not operate an engine without a thermostat. The cooling system incorporates a drain plug, on the left hand
side of the cylinder block. The cap on the radiator is a system pressure cap and should not be removed unless refilling
the system from empty.
The engine cooling fan is mounted on a pump pulley which is belt driven from the crankshaft.
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