The cooling system has the following components:
- Radiator
- Water pump
- Cylinder block
- Oil cooler
- Exhaust gas cooler (NRS)
- Cylinder head
- Water temperature regulator (thermostat)
| |
| Illustration 1 | g03696556 |
|
Typical example (A) Coolant flow to Clean Emissions Module (CEM) (B) Coolant flow from Clean Emissions Module (CEM) (1) Radiator (2) Water temperature regulator and housing (3) Exhaust gas cooler (NRS) (4) Cylinder head (5) Cylinder block (6) Water pump (7) Engine oil cooler | |
The coolant flows from the bottom of the radiator (1) to the engine oil cooler (7). The engine oil cooler (7) is installed on the right-hand side of the engine. The coolant flows from the engine oil cooler (7) to the water pump (6).
The water pump (6) contains a rotary seal that uses the engine coolant as a lubricating medium. This will ensure that an adequate sealing film is created. The sealing film is maintained in order to reduce heat generation. Heat that is generated by the rotating sealing faces under normal operating conditions causes a small flow of coolant to be emitted into a chamber. The water pump pumps the coolant through a passage to the main coolant gallery in the cylinder block (5).
Coolant flows around the outside of the cylinders then flows from the cylinder block (5) into the cylinder head (4).
The coolant flows forward through the cylinder head (4). Some coolant is diverted into the exhaust gas cooler (NRS) (3) by a coolant pipe in the right-hand side of the cylinder block (5). The coolant then flows from the exhaust gas cooler (NRS) (3) back to the housing of the water temperature regulator (2).
The coolant then flows into the housing of the water temperature regulator (2). If the water temperature regulator is closed, the coolant goes directly through a bypass to the inlet side of the water pump. If the water temperature regulator is open, and the bypass is closed then the coolant flows to the top of the radiator (1).
Coolant flows from the coolant adaptors in the cylinder block to the Clean Emissions Module (CEM). A secondary coolant circuit heats the Diesel Exhaust Fluid (DEF) tank and DEF pump. An additional coolant circuit cools the DEF injector in the CEM. The coolant flows from the CEM back to the inlet of the water pump (6). The inlet of the water pump is the low-pressure side of the water pump.