The engine (or cylinder) block is the large casing that contains the cylinders and many of the internal components of the engine.

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 main computer or powertrain control module (PCM) uses pre-programmed software to analyze the input received from sensors and produce output signals to adjust vehicle performance and operation. (Engine control unit (ECU) is another name for the PCM.)

The fluid reservoir stores the brake fluid that the master cylinder uses to maintain hydraulic pressure.

A connecting rod employs a wrist pin to link each piston to the engine's crankshaft.