An internal combustion engine relies on a full-pressure lubrication circuit to reduce friction and prevent premature component failure. In what sequence does engine oil circulate through the lubrication system starting from the oil reservoir and ending at the cylinder head valvetrain?
- 1Oil passes through the mesh strainer of the pickup tube in the oil pan sump.
- 2Oil enters the positive-displacement oil pump to be pressurized.
- 3Pressurized oil is forced through the full-flow oil filter element.
- 4Oil enters the main oil gallery to lubricate the crankshaft main and connecting rod bearings.
- 5Oil flows upward through cylinder head passages to lubricate the camshaft and valvetrain components.
Answer
The correct sequence of engine oil flow is: Oil pan pickup tube strainer → Oil pump pressurization → Oil filter filtration → Main engine block gallery and crankshaft bearings → Cylinder head passages and camshaft valvetrain.
In a standard automotive full-pressure lubrication system, oil is drawn from the reservoir in the oil pan through the pickup screen by the oil pump. The pump pressurizes the fluid and forces it through the full-flow oil filter to trap abrasive contaminants. From the filter, clean oil enters the main oil gallery in the engine block, feeding the crankshaft main and connecting rod bearings. Oil then travels upward through vertical galleys into the cylinder head to lubricate camshaft journals, pushrods/lifters, and rocker arms, after which it drains back into the oil pan via gravity.
Step-by-Step Solution
Key Concept
Engine lubrication circuit flow path and component order
Estimated Time:1m 30s