1. Engine Lubrication
Chapter 12

2. Objectives
Describe engine lubrication under different service conditions
Select the correct engine oil to use
Describe the operation of different types of oil filters

3. Introduction All moving parts are separated by a thin oil layer
Oil pump supplies oil to the engine
Little wear should occur if oil is maintained properly

5. Engine Oil More than basic crude Does more than lubricate
Contains a complicated additive package
First additives were developed in the 1930s
Does more than lubricate
Cools, cleans, and prevents rust
Fills hydraulic valve lifters or cam followers
Helps seal piston rings against cylinders

6. Engine Oil (cont'd.) Oil level
Correct level is designed to keep the oil pickup screen below the level of the oil
When checking oil level:
Vehicle should be on a level surface
Engine should be warm but off for five minutes
Push dipstick all the way down
If level is unclear: look at back of dipstick or re-dip
If level is low: check if the vehicle is due for service

9. Engine Oil (cont'd.) Oil viscosity Multiple viscosity oils
Oil thickness or body
Multiple viscosity oils
Most new engine oils are multiple viscosity
Viscosity index
Ability to resist change in viscosity under increased heat

10. Engine Oil (cont'd.) Oil pressure
Develops when there is a resistance to flow
As engine wears, clearance between crankshaft and bearings increases
Oil pump cannot fill extra clearance
Oil pressure is low when engine idles
SAE 20W-50 provides higher oil pressure in older, idling engines
Flows more slowly to bearings of new engine when first started on a cold morning

11. Engine Oil Licensing and Certification
SAE decides when new oil specifications are needed
American Society for Testing and Materials
Sets performance specifications
American Petroleum Institute
Administers the licensing and certification
Starburst symbol
API licenses engine oil marketers to display its starburst certification mark

13. Engine Oil Licensing and Certification (cont'd.)
Oil service ratings
Set by API
SA through SN
SA: mineral oil with no additives and is not recommended for automotive use
S: used for engines with a spark
Diesel engine oils: rated CA through CJ

14. Engine Oil Licensing and Certification (cont'd.)
European ACEA oils
ACEA standards developed by European auto manufacturers
Manufacturer-specific oil standards
Becoming more common
Energy-efficient oils
Oil is energy conserving if it passes certain tests
Energy conservation ratings began in 1994
HTHS viscosity rating
Measures viscosity under difficult conditions

15. Oil Additives
Additives make up as much as one-third of the volume of the oil
Additives found in engine oil
Pour-point depressants
Corrosion and rust inhibitors
Antifoam additives
Friction modifiers
Oxidation inhibitors
Antiwear additives

16. Oil Additives (cont'd.) Boundary lubrication
Film becomes too thin or breaks down under load
Detergents and dispersants
Keep small particles suspended
As oil decomposes at high temperatures it reacts with oxygen to form a gummy mixture
Detergents make deposits oil soluble
Sludge
Mixture of moisture, oil, and contaminants
Clogs oil screen and oil lines if it accumulates

18. Oil Additives (cont'd.) Nondetergent oil
Oil without additives is called
Oil oxidizes at temperatures higher than 250°F
Becomes thicker and forms varnish deposits
Oxidation rate doubles every 20°F above 140°F
Antioxidants combat the effects of heat on the oil
Detergents make varnish oil soluble

19. Synthetic Oils Molecules are nearly the same size
Reduces friction
Contain no wax or impurities
Suited to lower temperatures
Can also withstand higher temperatures
Advantages
Lower oil consumption
Can be changed less frequently
Disadvantage
Price

20. Changing Engine Oil Benefits of changing the oil Oil change intervals
Oil additives are depleted over time
Cleans smaller contaminants from the oil
Unburned contaminants are removed with the oil
Sludge is removed
Oil change intervals
Vehicles driven primarily on the highway can change oil every 7,500 miles
Newer engines with VTT require regular oil changes with high-quality, low-viscosity oil

21. Changing Engine oil (cont'd.)
Changing brands of oil
Avoid mixing brands between oil changes
Best done when the oil is being changed
Use any brand of high-grade oil when there is no choice of brand available
Changing oil
Best to change oil when it is still hot
Mileage service record: usually a sticker
Oil monitor system reset
Included in many late-model vehicles

23. Oil Filter
Prevents harmful abrasive particles in the oil from damaging internal parts
Today's cars use the full-flow oil filter
Must have a by-pass valve
Horizontal mounted filters
Have an anti-drainback valve
By-pass oil filters
Supplemental add-on filters used on heavy trucks
Variations in filters
Identified by a number printed on the metal shell

25. Changing the Oil Filter
Considerations
Sheet metal shell on filter is very thin
Rubber O-ring seals filter against engine block
Make sure there is not an old seal stuck to the engine block
Lubricate the O-ring with oil prior to installation
Most filters have instructions printed on the outside
Overtightening will make future removal difficult