| |
| Illustration 1 | g00942455 |
|
(1) Engine oil filter
(2) Engine oil cooler (3) Oil supply line for the turbocharger (4) Oil return line from the turbocharger (5) Engine oil level gauge (6) Engine oil pan (7) Drain plug | |
Oil Flow through the Oil Filter and Oil Cooler
| |
| Illustration 2 | g00291431 |
|
Lubrication system schematic (1) Flow of engine oil to the main engine oil gallery (2) Engine oil supply for the turbocharger (3) Return of engine oil from the turbocharger (4) Engine oil filter (5) Bypass valve for the engine oil filter (6) Engine oil pan (7) Engine oil pump (8) Bypass valve for the engine oil cooler (9) Suction bell (10) Engine oil cooler | |
Engine oil pump (7) is driven by the front gear train. The engine oil pump pulls engine oil from engine oil pan (6) through suction bell (9). The suction bell has a screen in order to strain large debris from the engine oil.
The engine oil pump has a relief valve that controls the pressure of the engine oil from the engine oil pump. If the engine oil pressure from the pump becomes excessive, the relief valve opens and some of the engine oil returns to the engine oil pan. This prevents high pressure engine oil from damaging the O-ring seals for the engine oil cooler and for the engine oil filter.
Engine oil filter (4) and engine oil cooler (10) have bypass valves (5) and (8). When the engine is cold, the pressure forces the bypass valves open. This provides immediate lubrication to the engine when cold engine oil with high viscosity causes a restriction.
After the engine warms up, the differential pressure on the bypass valves decreases and the bypass valves close. The engine oil flows normally through the engine oil cooler and through the engine oil filter.
The bypass valves will also open if there is a restriction in the engine oil cooler or in the engine oil filter. This allows the engine to be lubricated if the engine oil cooler is plugged or if the engine oil filter is dirty.
The engine oil is filtered and cooled. Clean engine oil is pumped to main engine oil gallery (1).
Filtered engine oil is pumped through supply line (2) for the turbocharger. Engine oil from the turbocharger returns to the engine oil pan through return line (3) at the rear of the cylinder block.
| |
| Illustration 3 | g00743424 |
|
(1) Bracket for rocker arm shaft
(2) Rocker arm shaft (3) Passage to valve lifters (4) Valve lifter bore (5) Supply to the rocker shaft bracket (6) Rocker arm shaft (7) Supply to the rocker shaft bracket (8) Passage to accessory drive (9) Passage to rocker shaft bracket and accessory drive (10) Passage to idler gear shaft (11) Passage to rocker shaft bracket (12) This opening is plugged. (13) Camshaft bearing (14) Piston cooling jet (15) Main bearing (16) Main engine oil gallery (17) Suction bell (18) Supply from the engine oil filter | |
Engine oil is pumped from suction bell (17) to the engine oil filter and to the engine oil cooler. The engine oil is cooled and filtered. The engine oil flows through supply (18) to main engine oil gallery (16).
Engine oil is supplied to camshaft bearings (13) and to main bearings (15) through drilled passages. Drilled holes in the crankshaft supply engine oil from the main bearings to the connecting rod bearings.
The engine oil circulates around each camshaft journal. Engine oil flows through grooves in the bores of the camshaft bearings into passages (3) that are connected to valve lifter bores (4). These passages provide pressurized engine oil for the lubrication of the valve lifters.
Engine oil flows from valve lifter bores (4) through passage (11) to a passage in bracket (5). The pressurized engine oil supplies lubrication to rocker arm shaft (2). Engine oil also flows from the front bore of the main bearing through passage (9) to a passage in front bracket (7) for rocker arm shaft (6). The holes in the rocker arm shafts allow the lubrication of the valve mechanism components.
Engine oil from passage (9) also lubricates accessory drive (8) and idler gear shaft (10).
Engine oil from the main engine oil gallery is directed to piston cooling jets (14). The piston cooling jets are located in the engine block below each piston. The piston cooling jets provide lubrication and cooling to the components of the piston and the cylinder wall. Each piston cooling jet has two tubes. One of the tubes provides engine oil to the underside of the piston crown. The other tube directs engine oil into a cast gallery in the piston. This gallery provides engine oil to a manifold behind the ring band of the piston. This helps cool the piston crown.
After the oil has completed lubrication, the engine oil returns to the engine oil pan.