PrimaryโขโขโขโขCooling System Flow The primary cooling system cools the following components:
โโ engine block
โโ cylinder heads
โโ engine oil cooler
โโ turbocharger
โโ EGR cooler
Coolant is drawn into the pump inlet located in the front cover from the bottom radiator port and flows from the coolant pump through the front cover to the crankcase.
From the crankcase the coolant is routed to the cylinder heads, turbocharger, engine oil cooler and the heater core.
The coolant enters the turbocharger from a passageway in the engine block. The coolant exits by a tube mounted on the left side of the turbocharger and goes into the water crossover at the front of the engine.
Coolant is routed through the right valve cover to the EGR cooler and the EGR valve. Most of the coolant returns to the right valve cover, but there is a small outlet that goes to the degas bottle.
The inlet for the heater core comes off the front water crossover. The outlet goes into the bottom radiator hose where it attaches to the radiator.
The inlet for the engine oil cooler comes out of the left side of the engine block. The outlet goes into the bottom radiator hose where it attaches to the front cover.
A dual thermostat system controls the flow of return coolant to the radiator. If the thermostats are open, coolant flows to the radiator to be cooled. If they are closed the coolant circulates through a bypass passage in the left cylinder head and engine block and return to the pump inlet.