Even though it is not necessary these days for the driver to understand how the car works it can be advantageous when it comes to dealing with mechanics, getting the best out of your car and looking after your car.
There are many different designs of engine but most of them are based around the four stroke principle. There are four phases or cycles involved to generate power. The combustion chamber inside and engine has two openings. The first is the inlet valve which allows the fuel and air mixture from the carburettor into the chamber. The second is the exhaust valve where burnt gases are expelled through. Beneath these a piston attached to the crankshaft.
As the piston moves down the volume inside the chamber increases drawing the fuel/air mixture into the chamber. When the piston gets to the bottom of it is cycle the inlet and outlet valves are both closed. As the piston is raised the fuel their mix is compressed, making it hotter and more volatile. When the gas is ignited it expands and forces the piston down at this point the exhaust valve is open and there burnt gas is expelled. The downward force of the piston causes the crankshaft to turn.
It is vital that the piston is adequately lubricated and this is the function of motor oil. Without lubrication the piston would wear away inside the cylinder as it travels back and forth. It would also get extremely hot, hot enough to melt. This is why a good quality motor oil has to be used. The oil pump circulated motor oil through the engine. Not having enough oil is extremely damaging to the engine. The first sign of low oil will come from the oil pressure gauge or your engine oil warning light. If these are not working the first indication you receive might be from a knocking noise inside the engine. Do not drive in these circumstances, always take action to get oil problems remedied.