Location
The oil/coolant module (1) is located on the right side of the engine.
Shown on engine 935 |
1 | Oil/coolant module |
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Task
The oil/coolant module (1) combines a number of components into one device and has the following tasks:
Delivery of the coolant (A) through the coolant circuit
Controlling the coolant temperature
Controlling the silicate concentration in the coolant (A)
Heating the engine oil (B) during the warm-up phase of the engine, and cooling the engine oil (B) after the operating temperature has been reached
Filtering the engine oil (B)
Body, shown on oil/coolant module (1) without centrifuge |
1 | Oil/coolant module |
2 | Oil filter cover |
3 | Oil filter element |
4 | Housing |
5 | Heat exchanger |
6 | Coolant pump |
7 | Silicate cartridge |
8 | Twin thermostat |
9 | Thermostat cover |
10 | Coolant inlet fitting |
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W18.20-1041-79
Function, shown on oil/coolant module (1) with centrifuge |
1 | Oil/coolant module | B604 | Oil pressure sensor | |
3 | Oil filter element | A | Coolant | |
5 | Heat exchanger | B | Engine oil | |
6 | Coolant pump | HR | Heater return | |
7 | Silicate cartridge | KA | Coolant outlet | |
8 | Twin thermostat | KE | Coolant inlet | |
10 | Coolant inlet fitting | OA | Engine oil outlet | |
11 | Coolant connection (coolant short-circuit loop) | OE | Engine oil inlet | |
12 | Coolant return from the AdBlue® heating (on model 800.010/012/210/220 with Euro VI Standard engine version) | OR | Engine oil return line |
Function
Delivery of the coolant (A) through the coolant circuit
The coolant (A) in the cooling system is brought into circulation by the coolant pump (6).
Controlling the coolant temperature
The coolant temperature is regulated over the twin thermostat (8).
When the engine is cold, the coolant pump (6) makes the coolant (A) circulate inside the engine. The coolant (A) from the coolant short-circuit loop flows over the coolant inlet (11) into the oil/coolant module (1) where it is routed at the closed twin thermostat (8) past the coolant pump (6) back into the crankcase.
When the engine operating temperature is reached, the cooler circuit is activated when the twin thermostat (8) is opened. The coolant (A) is fed via the coolant outlet (KA) to the radiator. The cooled coolant (A) again passes into the coolant circuit over the coolant inlet (KE) at the coolant inlet fitting (10).
Controlling the silicate concentration in the coolant (A)
The silicate concentration in the coolant (A) is controlled with the aid of the silicate storage unit (7) in order to protect the assembly parts in the engine from corrosion. The silicate crystals in the silicate cartridge (7) dissolve over time according to the silicate concentration (sometimes quicker, sometimes slower). The silicate cartridge (7) is therefore a maintenance part.
Heating and cooling the engine oil (B)
The engine oil (B) delivered by the oil pump enters the oil/coolant module (1) via the engine oil inlet (OE). Here the engine oil (B) is passed by into the heat exchanger (5) at the wastegate of the heat exchanger (5).
The bypass valve of the heat exchanger (5) opens from a certain pressure in order to protect the oil-water heat exchanger (5) from getting damaged if the engine oil is too thick, for example in the cold start phase of the engine.
The heat exchanger (5) consists of a number of pans which alternatively carry flowing coolant (A) and engine oil (B).
In the warm-up phase of the engine, the pans assume the temperature of the coolant (A) and give up heat to the flowing engine oil (B) - in doing so they heat up the engine oil (B).
After the warm-up phase of the engine the pans assume the temperature of the engine oil (B) and pass this on to the coolant (A). The engine oil (B) is cooled.
Filtering the engine oil (B)
After the engine oil (B) has passed through the heat exchanger (5), it enters the oil filter housing. Here the engine oil flows from the outside inwards through the oil filter element (3) and on to the support dome, where it is filtered.
The worm-shaped characteristic of the support dome routes the filtered engine oil (B) 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 (B) is initially routed downwards and then to the rear of the oil/coolant module (1) where the engine oil outlet (OA) is located. The filtered engine oil (B) then flows through the engine oil outlet (OA) and into the crankcase and the oil duct located there, and thus back into the oil circuit.