Modern car engines are cooled by liquid which circulates through the engine block and cylinder heads absorbing excess heat. This liquid is made up of half water and half antifreeze (commonly, ethylene glycol) which both keeps the water from freezing at low temperatures and raises its boiling point making heat transfer more efficient.

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.

Like CV joints, universal joints (U-joints) are located at each end of a drive shaft and allow the shaft to operate at a variable angle with the item it is driving. Universal joints perform the same basic function as CV joints but CV joints have a wider range of operation.

The thermostat controls coolant (and, through it, engine) temperature by regulating the flow of coolant through the radiator. A bypass tube allows coolant to bypass the radiator and flow back into the water pump when its temperature is low enough that the thermostat is closed.

The four-stroke piston cycle of internal combustion engines starts with the piston at top of the cylinder head (top dead center or TDC) during the intake stroke. The piston moves downward in the cylinder creating a vacuum that pulls an air-fuel mix into the combustion chamber through the now open intake valve.