How Your Car Works

Hello and welcome back to our series on automotive tools and how to guides for the new weekend warrior auto mechanic. This isn't meant for the professional, but rather the average Joe who is looking to get his hands a little dirty on the weekends. In the past, we have covered a lot of tools but in today's article I'm going to cover the basic things that make a car work from start to finish. This is just an overview of what occurs so you have a basic understanding to begin diagnosing any problems you may have.

When you first start your car you turn the ignition key. This closes a switch that sends a large electrical charge to your car's starter. The start will engage the flywheel and begin to turn it rapidly. That's the groaning sound that you hear before your car actually starts and runs smoothly.

The fuel now runs from the gas tank up to your engine compartment. The fuel pump pushes fuel through a fuel filter and down a line to your intake manifold. If your car has a carburetor, the fuel enters it and mixes with the air at this point. If your car is fuel injected, as most cars after 1987 are, it flows to the fuel injectors which are controlled by the computer.

Each pound of fuel is mixed with approximately 15 lbs of air. Ideally it should be 14.7 pounds of air for every one pound of fuel. Because the liquid fuel is much heavier than the air, it works out to be about 9000 parts of air for every 1 parts of fuel, by volume. Basically your car runs on air and has a little fuel mixed in to help it along.

The spark plug then fires, igniting the fuel and air mixture.

This ignition then pushes the piston head downwards with more force than it come up with.

The piston is attached to a connecting rod that is then attached to the crankshaft. This in turn spins the crankshaft which will allow the wheels to turn down the road.

On the working end of the crankshaft is your transmission. The transmission allows the engine to use various gear ratio's to aid it's mechanical leverage. If you have a manual transmission there is a clutch between the engine and transmission that physically connects or disconnects the engine from the transmission.

When you shift into first, it allows the drive shaft which is behind the transmission to turn at a certain rate of speed depending on the gear you are in.

In a rear wheel drive car, the drive shaft connects to the differential which in turn will spin each axle and the tires connected to them. In a front wheel drive car there is no drive shaft and the differential is built into the transmission case. The differential will still turn two axles, each connected to a tire.

And there you have it. Now you know how power gets from the engine to the tires to move the car forward or backwards.

Hopefully you enjoyed this overview. We hope you visit Sean's other review at JBL WIRELESS SPEAKERS.