The coolant pump is installed between the two
cylinder banks, on the front face of the cylinder
block. The pumping element is a shrouded
composite impeller. Coolant escapes from seal
breather holes in the housing if the pump's
bearing seal fails.
An O-ring and an edge bonded rubber/aluminum
alloy gasket seal the pump to cylinder block
interface. The O-ring seals the inlet port from the
thermostat. The gasket seals the outlet ports into
the cylinder banks.
The composite thermostat housing is installed
between the two cylinder banks, immediately
above the coolant pump. The thermostat controls
the flow of coolant through the radiator. It starts
to open at 80 to 84°C (176 to 183˚F) and is fully
open at 96°C (205˚F).
A duct in the cylinder block connects the
thermostat housing outlet to the pump inlet. A
stub pipe connects the duct to the air conditioning
heater matrix return line.
An in-groove gasket seals the joint between the
thermostat housing and the cylinder block.
In addition to containing the thermostat, the
composite thermostat housing incorporates
connections for the bleed, bypass and radiator
bottom hoses. The bleed outlet vents any air in
the system into the vehicle's coolant reservoir.
The cap of the thermostat housing is removable,
to allow air out of the system when filling from
CAUTION: Use the correct torque (marked on
the cap) when re-installing the
cap, or the cap/thermostat
housing could be damaged.
Supply and return hoses for the air conditioning
heater matrix are installed between the cylinder
A connection at the rear of A bank provides the
coolant supply for the electronic throttle and the
EGR valve. The outlet from the EGR valve
connects to the return hose of the air conditioning