W18.20-1032-06
Location
1 Oil/coolant module
The oil/coolant module (1) is located on the left side of the engine.
Task
The oil/coolant module (1) is used to:
Filter the engine oil
Regulate the engine oil temperature
Regulate the coolant temperature
Support the coolant pump
W18.20-1037-82
Body
1 Oil/coolant module
2 Oil thermostat
3 Oil filter
4 Oil filter cover
5 Oil/water heat exchanger
6 Coolant pump
7 Coolant thermostat
W18.20-1038-75
Function
1 Oil/coolant module
3 Oil filter
5 Oil/water heat exchanger
6 Coolant pump
7 Coolant thermostat
8 Initial filling valve
9 Engine oil inlet (from oil pump)
10 Engine oil outlet (to main oil ducts in crankcase)
11 Engine oil drain from oil filter (for oil filter change)
12 Coolant outlet (to crankcase)
13 Coolant inlet (from coolant bypass duct)
14 Coolant outlet (to exhaust gas recirculation cooler)
15 Coolant inlet (from coolant expansion reservoir, when the coolant expansion reservoir is at the front or the heater return, when the coolant expansion reservoir is at the rear)
17 Coolant inlet (return from compressor and fuel cooler)
18 Coolant inlet (from cooler)
A Coolant
B Engine oil
16 Coolant inlet (from coolant expansion reservoir, when the coolant expansion reservoir is at the rear or the heater return, when the coolant expansion reservoir is at the front)
Filter the engine oil
The engine oil flows, depending on the position of the oil thermostat (2), either straight into the oil filter housing (3) or after it has passed through the oil-water heat exchanger (5).
In the oil filter housing the engine oil flows from the outside inwards through the oil filter (3) and on to the support dome, where it is filtered The worm-shaped characteristic of the support dome routes the filtered engine oil upwards to the tip of the support dome, where it flows in through several holes in the support dome. Within the support dome the engine oil is initially routed downwards and then to the rear of the oil/coolant module (1), where the engine oil outlet (10) is located. The filtered engine oil then flows through the engine oil outlet (10) into the crankcase and the main oil ducts located there, and therefore back into the oil circuit.
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Regulate the engine oil temperature
To regulate the engine oil temperature an oil thermostat (2) is located immediately downstream of the engine oil inlet.
At an engine temperature of less than 115 °C the engine oil is routed through the open oil thermostat (2) over a bypass straight into the oil filter (3). At 115 °C the oil thermostat (2) closes the bypass and the engine oil flows first to the oil-water heat exchanger (5) before reaching the oil filter (3).
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Regulating the coolant temperature
The coolant temperature is regulated through the coolant thermostat (7). When the engine is cold, the coolant pump (6) makes the coolant circulate inside the engine. The coolant from the coolant short-circuit duct flows over the coolant inlet (13) into the oil/coolant module (1) where it is routed at the closed coolant thermostat (7) past the coolant pump (6) to the coolant outlet (12). When the engine operating temperature is reached, the cooler circuit is activated when the coolant thermostat (7) is opened.
The coolant from the cooler flows over the coolant inlet (18) and the open coolant thermostat (7) into the oil/coolant module (1).
Depending on the position of the coolant thermostat (7), more or less coolant flows through the cooler or directly over the coolant bypass line to the coolant pump (6). The temperature of the coolant in the coolant circuit is regulated in this way.