The cooling system has the following components:
- Radiator
- Water pump
- Cylinder block
- Oil cooler
- Exhaust gas cooler (NRS)
- Cylinder head
- Water temperature regulator
| |
| Illustration 1 | g03041237 |
|
Typical example (A) Coolant flow from Clean Emissions Module (CEM) (1) Radiator (2) Water temperature regulator and housing (3) Bypass for the water temperature regulator (4) Exhaust gas cooler (NRS) (5) Cylinder head (6) Cylinder block (7) Engine oil cooler (8) Water pump (B) Coolant supply to Clean Emissions Module (CEM) | |
The coolant flows from the bottom of the radiator (1) to the centrifugal water pump (8). The water pump (8) is installed on the front of the timing case. The water pump (8) is driven by a gear. The gear of the fuel injection pump drives the water pump gear.
The water pump (8) 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 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 (8) pumps the coolant through a passage in the timing case to the front of the cylinder block (6).
The coolant enters a passage in the left side of the cylinder block (6). Some coolant enters the cylinder block. Some coolant passes over the element of the oil cooler (7). The coolant then enters the block (6). Coolant flows around the outside of the cylinders then flows from the cylinder block into the cylinder head (5).
Some coolant flows through a cavity in the cylinder head (5). Some coolant is diverted into the exhaust gas cooler (4) by a coolant pipe in the rear of the cylinder head (5). The coolant then flows out of the exhaust gas cooler (4) to the cavity in the front of the cylinder head (5).
Some additional coolant flows from the cylinder block to the Back Pressure Valve (BPV). The coolant then flows from the BPV to the inlet coolant pipe for the exhaust gas cooler (4).
The coolant then flows into the housing of the water temperature regulator (2). If the water temperature regulator (2) is closed, the coolant goes directly through a bypass (3) 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 top of the cylinder head (5) 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 top of the water pump (8). The top of the water pump is the low-pressure side of the water pump.