23
N73B60 Engine - Diagnosis
The coolant flows to the rear of the engine block, from there through the side channels to
the cylinder walls and then into the cylinder heads (lower left picture). The cast aluminum
cover at the rear of the engine block (with sealing bead) is shown on the lower right.
Water Pump/Thermostat Housing
The water pump is combined with the thermostat housing and is bolted to the timing case
lower section.
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The impeller is made from reinforced plastic.
• Reassemble engine using your notes taken during disassembly in addition
to the Repair Instructions.
42-02-59
Water Pump / Thermostat Housing
1. Map-controlled themostat (radiator cool return flow).
2. Electrical connection for Thermostat Heating element.
3. Thermostat Mixing Chamber
4. Temperature Sensor (hot coolant from engine)
5. Radiator in-flow (hot coolant from engine)
6. Heat exchanger (transmission oil return flow)
7. Leakage Chamber (evaporation space)
8. Alternator in-flow (cool supply)
9. Water Pump
10. Expansion Tank Connection
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