User Manual

Coolant Flow
Illustration 17 g02847496
Typical example
(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).
20 UENR0623-02
Engine Operation
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