How Cars Work

This page is here to provide you with a basic understanding of the function of each component of your car.

Engine
- The heart of the car. This is what provides your car with power. There are several variations of engines. Different layouts and cylinder number options.

Engine Components:
Alternator
- This is the electrical charging component that is belt driven and keeps the battery charged and electronics running. If this gives out your car can temporarily run off of battery power, but not for long. Look at the picture below, alternators always look like this.

Air Conditioning Compressor
- This is a belt driven component that is the work horse of your air conditioning system. It compresses the refrigerant to a point that it cools a metal grill (called an evaporator) and air passes over it to be cooled and then into the car. You can identify it by the hard pipes, that lead from it as well as the plastic caps on those lines with H (for high pressure) and L (for low pressure).

You can also identify it because the pulley has a clutch mounted to it (for allowing the motor to spin without always running the AC) it generally looks like this.

Power Steering Pump
- This belt driven hydraulic pump is what makes it so easy to turn your steering wheel. I'm sure most of you haven't driven a vehicle without power steering, its not fun. This pump pushes pressurized fluid into your lower steering components. If this fails, you can still drive your car, its just harder to turn, especially when sitting still. You can normally identify these easily by the fluid reservoir on top, but not always, this is my dad's 01 Forester, but on my 01 Outback the reservoir is mounted on the body of the car, while the pump sits on the motor.

Brake Master Cylinder
- This component is a hydraulic cylinder that is mechanically connected to the brake pedal. It applies pressurized fluid to the calipers (disc brakes) or wheel cylinders (drum brakes) and then clamps the friction material to the metal to slow your car. This component is ALWAYS mounted to the back of the engine bay in front of the drivers side. If this component fails, you will have no brakes. Not good.

Throttle Body
- This component is either connected to the gas pedal via a cable or electronically. As you apply gas, a valve opens which allows more air to enter the motor, making it spin faster and create more power. The all look the same. You can see the cables hooked up below. One is for the gas pedal, the other is connected to the cruise control system.