Engine Lubrication System - Suzuki XL7 2007 Service Manual

1E-1 Engine Lubrication System:

Engine Lubrication System

General Description
Lubrication Description
A structural diecast aluminum oil pan incorporates an oil suction tube, a baffle, a windage tray and an oil level sensor.
The oil suction tube is bolted into the oil pan and seals to the bottom of the block with O-ring gasket. The baffle is
mounted to the lower portion of the 6-quart capacity oil pan sump and ensures oil supply to the oil suction pickup. The
windage tray is bolted to the upper portion of the oil pan and reduces friction losses at high speed. The oil level sensor
is mounted through the bottom of the oil pan.
A crankshaft driven gerotor oil pump with internal pressure-relief valve is mounted to the front of the engine block and
pulls oil from the oil suction tube through the lower passage in the engine block. The oil pump then directs the flow of
pressurized oil back through the upper passage in the block to the left side of the engine block where the oil filter
adapter is mounted.
An oil filter adapter is mounted with a gasket to the left side of the engine block. The oil filter adapter incorporates a
bottom-access, spin-on oil filter. The oil filter adapter housing incorporates a built-in oil bypass valve and a threaded oil
pressure sending unit. Oil flows through the lower passage in the oil filter adapter to and through the oil filter. Filtered
oil travels back through the upper passage of the oil filter adapter and back into the engine block.
Oil is directed up and across the engine block front through several drilled passages. These front passages feed oil to
each cylinder head, oil to the passage for the main bearings and piston oil jets, oil to the right and left secondary idler
sprockets and oil to the primary timing drive chain tensioner.
Each cylinder head passage directs oil into the cylinder head where it is directed to oiling circuits for the stationary
hydraulic lifter assemblies (SHLAs) and the camshaft bearing journals. Oil is also directed through two passages each
with a spring-loaded check-ball valve to the two chambers where the camshaft position actuator oil control solenoid
valves are mounted. Each chamber contains a camshaft position actuator oil control solenoid valve with built-in oil
filter screen. One camshaft position actuator oil control solenoid valve is used to control the exhaust camshaft position
actuator and one camshaft position actuator oil control solenoid valve is used to control the intake camshaft position
actuator. The engine control module (ECM) electrically controls each camshaft position actuator oil control solenoid
valve. When energized by the ECM the camshaft position actuator oil control solenoid valve directs oil to pass up
through the cylinder head front camshaft bearing cap. Oil passes through the camshaft bearing cap passage into oil
holes drilled into the side of the front camshaft journal and onto the front of the camshaft mounting surface. Oil passes
through to matching passages in the camshaft position actuator. Oil is directed by the camshaft position actuator oil
control solenoid valve to the appropriate passage in the system to pressurize oil on the vanes on the inside of the of
the camshaft position actuator. Oil acting on the vanes rotates the camshaft mounted to the inner camshaft position
actuator rotor relative to the sprocket mounted to the outer camshaft position actuator housing. An internal lock pin
locks the inner rotor to the outer camshaft position actuator housing at idle and maintains the camshaft position
actuator in the home or default position during start-up conditions. Oil pressure directed by the camshaft position
actuator oil control solenoid valve unlocks the pin and allows the camshaft position actuator to function. An additional
passage in the cylinder head also directs oil to the secondary timing drive chain tensioner mounted to each cylinder
head.
The oil passage that supplies oil to the main bearings also supplies oil to pressure-actuated piston-cooling oil jets.
Each oil jet is mounted between opposing cylinder bores and directs oil to the two bores to provide extra cooling and
control piston temperatures.
Oil is directed from the front passages to the front of the block where the right and left secondary idler sprockets and
the primary timing drive chain tensioner are mounted. Each camshaft timing drive chain tensioner relies on a gasket in
order to maintain an oil reserve after the engine is turned OFF. All camshaft timing drive chain tensioners incorporate a
small oil jet to supply an oil spray onto the camshaft timing drive chain components.
Oil returns to the oil pan sump either through the camshaft timing drive chain area or through the cast oil drain back
passages on the outboard walls of the cylinder heads and engine block.