The battery supplies the power necessary to start the engine when the ignition switch is is turned on.

The catalytic converter converts pollutants in exhaust gas into less pollutant substances like carbon dioxide and water.

The oil pan contains the engine oil reservoir of from four to six quarts of oil and feeds the oil pump through the oil pickup tube. An oil strainer floats at the top of the oil in the oil pan and screens debris from the oil before feeding it to the oil pump.

The lubrication system lubricates engine components by putting an oil film between them to reduce friction and smooth engine operation, cools by absorbing heat from engine parts, seals the pistons and cylinders to contain combustion, cleans contaminants, and quiets engine noise.

The water pump is driven by a belt connected to the crankshaft and ensures that coolant moves through the engine and radiator.