Chapter 13 Lubrication

Objectives Analyze wear and damage to lubrication system parts Explain lubrication system theory Select and perform most appropriate repairs to lubrication system

Oil Used to reduce friction Prevents internal engine components from rubbing against each other Partial breakdown of lubricating film is known as boundary lubrication

Viscosity Resistance of an oil to roll and flow Measurement of an oil’s thickness is also called weight When a “W” accompanies the rating Oil’s viscosity has been tested at 0 degrees Means that it is a winter blend

Oil Service Ratings API Ratings progress SA through SM SM is the latest rating “S” means the oil is for engine with spark ignition Diesel engine oil is rated from CA through CI “C” stands for compression ignition

Oil Service Ratings Diesel engine oil is rated from CA through CI “C” stands for compression ignition

Deterioration of Oil Oil never wears out Becomes diluted with unburned fuel and water

Deterioration of Oil 100 gallons of burned gasoline produce 90 to 120 gallons of water 3 to 10 gallons of unburned fuel 2 pounds of soot 1 pound of resins and varnishes 1 to 4 pounds of nitrogen and sulfur acids 1 to 2 ounces of hydrochloric acid

Oil Additives Detergents Antioxidants Antiwear additives Pour point depressants Corrosion inhibitors Antifoam additives Friction modifiers

Oil Additives

Synthetic Oils 1930s Compared to conventional oils Higher priced Outstanding low temperature characteristics Better viscosity index Increased fuel economy and power Higher priced Oil change frequency is less

Oil Pumps Driven by camshaft or crankshaft Three types of pumps External gear Rotor Internal and external gear Cast iron pumps are better than aluminum because they wear less

Oil Pumps

Oil Pressure Normal oil pressure at idle Low oil pressure About 25 psi Low oil pressure Indicates excessive bearing clearance or a worn pump High oil pressure Pressure relief valve stuck in closed position

Oil Pump Failure Wear or seize Improper engine maintenance Debris from broken or failed engine parts Hex drive shaft twists off because foreign material enters pump Seals and o-rings wear and deteriorate

Oil Pump Failure

Installing Oil Pump Check relief valve operation Retorque pump cover to specifications Ensure pump is properly aligned before bolting on Damage can occur

Installing Oil Pump

Priming the System Use priming tool hooked to an electric drill Insert priming tool into oil pump Drive tool slowly in direction of distributor rotation After pressure builds Rotate crankshaft one complete rotation Prime system once more

Pressure Priming Uses air pressure to push oil through system Used to locate excessive leakage from bearings Also to flush oil galleries during an in car engine repair

Pressure Priming

Filter Bypass Valve Bypass valve opens: Under heavy flow When the oil is cold and thick When the filter becomes plugged due to poor maintenance

Changing the Filter Use a filter wrench only to remove the filter Never to tighten it Oil rubber sealing ring on the base of the filter before installing it Ensure o-ring is in place on filter Tighten filter by hand only

Testing PCV System Pull valve from its mounting With engine running Cover end of valve with thumb

Testing PCV System Engine RPM should drop 50 to 80 rpm With engine running and pcv installed Should have vacuum at rocker cover oil filler opening With engine stopped PCV should rattle when shaken