The oil system Flashcards
Oil functions
- Reduces friction
- Provides cooling
- Removes contaminets
- Sealing (between the cylinder wall and the piston, prevents gases from esacping)
Oil filter
Removes dirt or carbon particles from the circulating oil
Scavenge pump
Used in dry sump to return oil back to the sump (scavenged from the engine)
In a wet sump system (172) the oil is returned to the sump by ____
gravity
The oil cooler is reached ______ (before / after) the filter
After it has been pumped from the sump
The oil temparature gauge shows the temparature _____ the oil cooler, and ____ the hot sections of the engine
After, before
High oil temprature may indicate
- Clogged oil line
- Low quantity of oil
- Blockage in oil cooler
- Malfunction temp. gauge
Low oil temprature may indicate:
- Incorrect type of oil being used during cold weather
- Malfunction temp. gauge
How come we can use Bourdon tube gauge (for sensing pressure) also for temprature?
Because pressure and temparature are related.
Oil quantity will gardually decrease because of?:
- Burning with the fuel/air mix in the cylinder
- Loss as a mist or spry through the oil breather
- Leaks
Low oil pressure could mean:
- Lack of oil due to a failure in oil system
- Insufficient oil
-A leak - A failure of oil pump
- A problem in the engine
- The oil pressure relief valve is stuck open
On start up, oil pressure should be displayed within ____ seconds
30
if oil pressure not displayed after 30 seconds after startup,
shut down immediately
Oil must be
viscous
Oil must have high flash point and fire point because
to prevent excessive vaporisation and to catch fire easily
Oil must be chemically stable
remember
Sump
After doing its work in the engine, gathers in the sump
Dry sump
The reservoir (oil tank) is separate from the engine
Oil pressure relief valve
If the pressure is excdeed, the valave opens allowing oil to be returned to the pump inlet
Where is the oil pressure measured
After the oil pump, before reaching the engine
High oil temparature may indicate a _____ in oil quantity
Decrease
Incase of a suspected oil problem,
land immediately
If oil temprate is gradully rising, that means
Slowly losing oil. Less oil has to do the same amount of work of lubricating and cooling,.
Wet sump
Oil is contained in a sump at the bottom of the engine and there’s no oil tank
