How to distinguish between a three-cylinder and a four-cylinder engine?
3 Answers
To distinguish between a three-cylinder and a four-cylinder engine, you can check the number of manifolds. A three-cylinder engine has three exhaust manifolds and intake manifolds, while a four-cylinder engine has four exhaust manifolds and intake manifolds. A three-cylinder engine consists of three identical single cylinders arranged on a single block sharing one crankshaft to output power, converting chemical energy into mechanical energy. A four-cylinder engine, also known as a four-cylinder engine, is a machine that converts one form of energy into another more useful form of energy. Its structure consists of the cylinder block, crankcase, cylinder head, and cylinder gasket components. The engine is the device that provides power to the car, determining its power, fuel efficiency, stability, and environmental friendliness.
I paid special attention to this issue during my last test drive. Simply put, the steering wheel of a three-cylinder engine vibrates noticeably more when idling, especially when the air conditioning is on and waiting at a red light. Placing your palm on the steering wheel, you can clearly feel the tremor. Four-cylinder engines basically don’t have this issue, and the power output is smoother at high speeds. Counting the exhaust pipes is the most straightforward method—most three-cylinder cars now have only one exhaust pipe, but remember to open the hood and double-check. There will be a '3' or '4' numeric label next to the cylinders. Additionally, a three-cylinder engine makes a stuttering 'putt-putt-putt' sound when starting, while a four-cylinder engine produces a continuous 'humming' sound.
I've worked on hundreds of engines in repair shops and can tell a three-cylinder from a four-cylinder just by the startup sound. The three-cylinder's firing order is different - at idle, the whole engine bay vibrates slightly, and if you rest your hand on the hood edge, you can feel the higher vibration frequency. Counting spark plug wires is more accurate though - lift the plastic engine cover and you'll see three ignition coil connectors neatly lined up. Modern three-cylinders now have balance shafts which help reduce vibration, but they still can't match four-cylinder smoothness, especially during cold starts when it's most noticeable.
