How Vehicle Engines Work

Problems With Your Engine? Our Idaho Falls Mechanics Can Help You Out


A lot of mechanics in Idaho Falls know that their area of expertise usually goes over the head of the layman, which is why C&S Auto Repair is here to help you get a better understanding of your vehicle engine.

For many of us, the inner workings of our vehicles are really a mystery. They take us from one place to another provided we feed them plenty of gas, change the oil, and keep the battery charged. Beyond that, most of our concerns are left to faith in the complex science that makes the internal-combustion engine work.

The Basics

visual representation of an vehicle engine

The internal-combustion engine is a heat engine, meaning the energy behind its moving mechanics is created from heat – specifically, the heat of burning gasoline. The energy that powers your engine’s mechanical work – otherwise known as “torque” – is directed to the wheels so that your vehicle can move. 

Inside your engine are spark plugs connected to cylinders – metal tubes that contain pistons that move up and down. The pistons are connected via rods to the crankshaft. The up-and-down motion of the rods and pistons turns the crankshaft. This spines your tires and moves your vehicle along the ground.

vehicle engine with identified parts

Our auto repair in Idaho Falls often involves maintaining and repairing these various engine parts.

What Powers The Engine

A fuel-oxygen mixture is ignited by the spark plugs to create thousands of small explosions per minute. Each explosion is called a combustion – hence the name internal-combustion engine.  The air-fuel mixture enters the cylinder via the intake valve, becomes ignited by the spark plug, and exits via the exhaust valve.

There are four ways the pistons move in the cylinders, called “strokes”. A stroke is the full travel of a piston along a cylinder from top dead center (T.D.C.) to bottom dead center (B.D.C.). Most modern engines are four-stroke engines.

car cylinders
  • Intake stroke

    Also called “induction” or “suction” stroke, this one starts at T.D.C. and ends at B.D.C. The intake valve is open so the piston can draw in the air-fuel mixture via vacuum pressure created by its downward motion. 
  • Compression stroke

    Intake and exhaust valves are closed during the compression stroke. Beginning at B.D.C. and ending at T.D.C., this stroke involves the piston compressing the air-fuel mixture to be later ignited. 
  • Combustion stroke

    Also called “power” or “ignition” stroke. The crankshaft has made a full 360 degree revolution at this stage and the piston is at T.D.C. A spark plug ignites the air-fuel mixture (in diesel engines this is accomplished with heat caused by high compression). The small explosion created launches the piston back to B.D.C, causing the engine to turn the crankshaft.
  • Exhaust stroke

    With the exhaust valve open, the piston goes from B.D.C. to T.D.C. again in this stage. The used air-fuel mixture is expelled through the exhaust valve.

And there you have it! The inner-workings of your internal-combustion engine. 

Remember, engine damage can mean death for your vehicle. If you have something going on with your engine, bring it in and have a professional mechanic take a look at it right away.

Another thing you need to keep up on is regular oil changes. Clean oil is required for all those moving parts in your engine to function smoothly and without too much friction.


We Service All Makes and Models

We Specialize in Repair on 1996 and Newer Domestic and Asian Vehicles
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