Location
The oil/coolant module (1) is located on the left side of the engine.
Shown on engine 471.9 |
1 | Oil/coolant module |
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Task
The oil/coolant module (1):
Filters the engine oil
Regulates the engine oil temperature
Regulates the coolant temperature
Supports the coolant pump
Structure
1 | Oil/coolant module |
2 | Oil thermostat |
3 | Oil filter |
4 | Oil filter cover |
5 | Heat exchanger |
6 | Coolant pump |
7 | Coolant thermostat |
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Function
1 | Oil/coolant module |
3 | Oil filter |
5 | Heat exchanger |
6 | Coolant pump |
7 | Coolant thermostat |
8 | Initial filling valve |
9 | Engine oil inlet (from oil pump) |
10 | Engine oil outlet (to oil ducts in crankcase) |
11 | Engine oil drain from oil filter (in case of oil filter change) |
12 | Coolant outlet (to crankcase) |
13 | Coolant inlet (from coolant short-circuit duct) |
14 | Coolant outlet (to exhaust gas recirculation cooler) |
15 | Coolant inlet (from coolant expansion reservoir if the coolant expansion reservoir is located at the front, or return flow from the heating if the coolant expansion reservoir is located at the rear) |
16 | Coolant inlet (from coolant expansion reservoir if the coolant expansion reservoir is located at the rear, or return flow from the heating if the coolant expansion reservoir is located at the front) |
17 | Coolant inlet (return flow from compressor and from fuel cooler) |
18 | Coolant inlet (from cooler) |
A | Coolant |
B | Engine oil |
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Filtering of engine oil
Depending on the position of the oil thermostat (2), the engine oil enters the housing of the oil filter (3) either directly or after it has passed through the heat exchanger (5).
In the oil filter housing, the engine oil flows from the outside through the oil filter (3) and inwards to the support dome, and is filtered in the process. 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. Inside the support dome, the engine oil is initially routed downward 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 oil ducts located therein, and thus back into the oil circuit.
Regulation of the engine oil temperature
There is an oil thermostat (2) located immediately downstream of the engine oil inlet (9); it regulates the engine oil temperature.
At an engine oil temperature below 115 °C, the engine oil is guided through the opened oil thermostat (2) and via a bypass directly into the oil filter (3). At 115 °C, the oil thermostat (2) closes the bypass and the engine oil flows through the heat exchanger (5) first, before it enters the oil filter (3).
Regulation of the coolant temperature
The coolant temperature is regulated via 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 via the coolant inlet (13) into the oil/coolant module (1), where it is guided past the closed coolant thermostat (7) and through 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 radiator enters the oil/coolant module (1) via the coolant inlet (18) and the opened coolant thermostat (7).
Depending on the position of the coolant thermostat (7), more or less coolant now flows through the radiator or directly via the coolant short-circuit duct to the coolant pump (6).
The temperature of the coolant in the coolant circuit is regulated in this way.