The engine lubrication system is of the force-feed
type. The oil is supplied under full pressure to the
crankshaft, connecting rods, valve lifters, camshaft,
and rear balance shaft bearing. A controlled
volume of oil is supplied to the valve rocker arms
and push rods. All other moving parts are
lubricated by gravity flow or splash. The engine oil
is stored in the lower crankcase (oil pan) which is
filled through a filler opening in the valve rocker arm
cover. A removable oil level indicator, on the left
side of the engine block, is provided to check the
oil level. The oil pump is located in the engine front
cover and is driven by the crankshaft. It is a
gerotor-style pump which is a combination of a
gear and a rotor pump. It is connected by a
passage in the cylinder block to an oil screen and
pipe assembly. The screen is submerged in the oil
supply and has ample volume for all operating
conditions. If the screen becomes clogged, oil may
be drawn into the system through the oil pressure
relief valve in the oil filter adapter.

Oil is drawn into the pump through the screen and
pipe assembly, and a passage in the crankcase,
connecting to the passages in the engine front
cover. Oil is discharged from the oil pump to the oil
filter adapter. The oil filter adapter consists of an oil
filter bypass valve and a nipple for installation of an
oil filter. The spring-loaded oil pressure relief valve,
located in the engine front cover, limits the oil
pressure. The oil filter bypass valve opens when the
oil filter is restricted to approximately 68.95 kPa (10
psi) of pressure difference between the oil filter inlet
and discharge. The oil will then bypass the oil filter
and channel unfiltered oil directly to the main oil
galleries of the engine. A full-flow oil filter is
externally mounted to the oil filter adapter on the
lower right front side of the engine. If the filter
element becomes restricted, not allowing engine oil
to pass through, a spring-loaded bypass valve
opens. The main oil galleries run the full length of
the engine block and cut into the valve lifter guide
holes to supply oil at full pressure to the valve
lifters. Holes, drilled from the crankshaft bearings to
the main oil gallery, intersect the camshaft bearing
bores to supply oil to the cam bearings.
3800 V6 Engine Oiling System Operation

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Oil is transferred from the crankshaft bearings to the connecting
rod bearings through holes drilled in the crankshaft. Pistons,
piston pins, and cylinder walls are lubricated by oil splash from
the crankshaft and connecting rods.

Each valve rocker arm and valve is supplied with oil through the
tubular push rod. The oil comes from the inside of the valve lifter
passing around the metering valve and through a hole in the
push rod seat. Oil from the push rod passes through a hole in the
push rod seat, and emerges on top of the push rod seat boss.