The engine is the power device of the car, which is composed of two major mechanisms and five major systems: crank connecting rod mechanism, valve mechanism, cooling system, fuel supply system, lubrication system, ignition system, starting system, but the diesel engine is less than the gasoline engine ignition system.

1. Cooling system: generally composed of water tank, water pump, radiator, fan, thermostat, water temperature meter and water release switch. Car engines are cooled in two ways, air cooling and water cooling. Generally, the car engine uses water cooling.

2. Lubrication system: The engine lubrication system is composed of oil pump, filter collector, oil filter, oil passage, pressure limiting valve, oil gauge, pressure sensing plug and dipstick.

3. Fuel supply system:

Gasoline engine fuel system includes gasoline tank, gasoline meter, gasoline pipe, gasoline filter, gasoline pump, carburetor, air filter, etc.

Diesel fuel system includes fuel injection pump, fuel injector and governor and other main components and diesel tank, oil delivery pump, oil and water separator, diesel filter, injection advance device and high, low pressure tubing and other auxiliary devices.

4. Starting system: starter, battery, etc.

5. Ignition system: spark plug, high voltage wire, high voltage coil, distributor, ignition switch, etc.

6. Crank connecting rod mechanism: connecting rod, crankshaft, bearing shell, flywheel, piston, piston ring, piston pin, crankshaft oil seal, etc.

7. Valve mechanism: cylinder cover, valve chamber cover camshaft, valve intake manifold, exhaust manifold, air filter, silencer, three-way catalytic supercharger, etc.