Automotive
Engine Lubrication Systems 

Main Components

• Oil Pump
• • The oil pump is the heart of the lubricating system. 
  • Just as the human heart circulates blood through veins and engine's oil pump circulates oil through passages in the engine. 

• Oil Pump Pickup

• • The oil pump pickup is a line from the oil pump to the oil stored in the oil pan. 
  • It usually contains a filter screen, which is submerged in the oil at all times.
  • The screen servers to keep large particles from reaching the oil pump. 

• Oil Pan or Sump

• • The oil pan attaches to the crankcase of block. 
  • It serves as the reservoir fro the engine's oil. 
  • It is designed to hold the amount of oil needed to lubricate the engine when it is running, plus a reserve. 
  • The oil pan helps to cool the oil through its contact with the outside air. 

• Pressure Relief Valve

• • Since the oil pump is a positive displacement pump, an oil pressure relief valve is included in the system to prevent excessively high system pressures from occurring as engine speed is increased. 
  • Once the oil pressure exceeds a preset limit, the spring-loaded pressure relief valve opens and allows the excess oil to by-pass the rest of the system and return directly to the sump or oil pan. 

• Oil Filter

• • All the oil that leaves oil pump is directed to the oil filter.  
  • This insures that very small particles of dirt and metal suspended in the oil will not reach the close fitting parts, causing premature wear. 

• Oil Filter Element

• • Oil from the engine's oil pump enters the filter and passes through the element of the filter. 
  • From the element, the oil flows into the engine's main oil gallery. 

•  Oil Filter Mounting

• • The filter is usually mounted and sealed to an adapter that bolts to the engine block. 
  • However, it may be remotely mounted with oil lines connecting the filter mount to the oil galleries in the engine block. 

• Drain Back Valve 

• • Some oil filters have an anti-drain back valves that prevents oil  drainage from the filter when the engine is not running.  
  • This allows for a supply of filtered oil to the engine as soon as the engine is started. 

• Full Flow Oil System

   
• • Today's engines have a full-flow oil system. 
  • All the oil going to the engine's moving parts goes through the filter first. 

• Plugged Filter

• • Should the filter become plugged, a relief valve in the filter opens and  allows the oil to bypass and go directly to the moving parts. 

• Engine Oil Passages or Galleries

• • From the filter, the oil flows into the engine  galleries. 
  • These galleries consist of interconnecting passages that have been drilled completely through the engine block during manufacturing. 
  • The crankshaft also contains oil passages to route the oil form the main bearing to connecting rod bearings surfaces. 

• Oil Pressure Indicators

   
• • A cars driver can monitor oil by looking at the gauge, which indicates the engines oil pressure at all times, or a warning light that will come on whenever the engine is running with insufficient oil pressure. 

• Oil Seals and Gaskets

• • These are used throughout the engine to prevent both external and internal oil leaks. 
  • The most common materials used for sealing are synthetic rubber, soft plastics, fiber, and cork. 
  • In critical areas, these materials might be bonded to a metal. 

• Dipstick

• • The dipstick is used to measure the level of oil in the oil pan. 
  • The end of the stick is marked to indicate when the engine oil level is correct. 
  • It also has a mark to indicate the need to add oil to the system. 

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