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► Lubrication oil is distilled from crude oil and has additives to prevent acid formation, reduce oxidation, and maintain correct viscosity.
► Functions of oil include reduces friction, cushions, cleans, cools, and seals.
► Viscosity refers to how easily a liquid flows.
► Oil additives include: extreme pressure additives, oxidation inhibitors, corrosion inhibitors, anti-foaming agents, detergents, dispersants, pour point depressants, and viscosity index improvers.
► Engine oil also works to suppress engine noise and protect against corrosion.
► The three types of oils are: conventional, synthetic, and synthetic blend.
► Conventional oil is refined from crude oil and requires additives to function effectively.
► Synthetic oil is developed in a lab, is longer lasting, operates at higher temperatures, protects better against engine wear, and is more costly to manufacture.
► Synthetic blends combine conventional and synthetic oils.
► The American Petroleum Institute classifies oil into groups 1–5.
► Components of a lubrication system include: oil pan, oil sump, pick-up tube, oil pump, oil pressure relief valve, oil filter, spurt holes, and gallery.
► Oil sump systems can be wet sump or dry sump.
► Types of oil pumps are: rotor type, crescent pump, and geared oil pump.
► The two most basic oil filtering systems are full-flow filters (most common) and bypass filters.
► Vehicles are equipped with oil indicators, oil monitoring systems, and some with an oil cooler.
► Types of lubrication systems are: splash, pressure (or force feed), two-stroke engine premix, or two-stroke engine oil injection.
► Common lubrication system issues are infrequent oil changes, oil leaks, and valve train noise due to low oil pressure.
► Tools used to diagnose the lubrication system include: oil pressure gauge, mechanic’s stethoscope, digital volt ohm meter, and fluorescent dye.
► Diagnosis of the lubrication system may include: oil analysis; checking engine oil; oil pressure testing; inspecting oil sensors; and inspecting the engine assembly for fuel, oil, coolant, and other leaks.
► Always check a vehicle’s service manual when changing engine oil to determine the correct quantity.
► If the vehicle’s oil pressure gauge reads low, verify this with a test gauge.
► Lubrication repair tools include: oil filter wrench, wrenches and socket set, mirror, good quality light, digital volt ohm meter, and a special socket for removing oil pressure switches or sensors.
► Maintenance and repair procedures include: draining the engine oil; replacing the oil filter; refilling engine oil; and inspecting, testing, and replacing oil pressure and temperature switches.