How does a car engine start?

This blog post will answer the question, ‘How does a car engine start?’, and cover topics like a step-by-step guide to starting and stopping a car engine, maintaining motion in a car, and how does a car engine start in cold weather.

How does a car engine start?

These are the following ways in which a car engine starts:

  • The hot combustion gases that are produced at high pressure inside the combustion chambers are used as the driving force for the piston movements which in turn, helps drive the wheels.
  • The combustion cycle starts with the inlet valve permitting the entry of the air-fuel mixture into the cylinder.
  • The piston reacts to this by moving downwards followed by compressing the air-fuel mixture as it moves upwards.
  • The compressed air-fuel mixture is then ignited by the spark plugs.
  • This ignition is done at very high pressure and the impact makes the pistons move downwards to transfer that power to the crankshaft via the connecting rod.
  • As discussed earlier, only the lower end of the connecting rod moves in a circular motion while the upper end stays fixed and restricted to linear motion.
  • The power is then transferred to the crankshaft that further sends it to the car wheels via a transmission system and the driveshafts.

A step-by-step guide to starting the car

Starting the car

The following steps need to be followed when attempting to start a car:

  • All the doors of the car need to be closed
  • The mirrors should be properly adjusted according to the driver’s position, to avoid other cars and civilians
  • It is important to ensure that all the seat belts are strapped and the seatbelt sign turns off
  • The handbrake must be released
  • The car gear should be in a neutral position
  • Choke if necessary
  • Hold the steering wheel at 9 o’clock and 3 o’clock, lightly but firmly
  • Depress the clutch pedal fully
  • Press and release the starter as the engine comes alive, delay will damage the starter and flywheel
  • Raise engine speed up to 1000rpm and no further
  • Release clutch and cancel choke when the engine runs evenly
  • Check all gauges like the ammeter, temperature, fuel,  oil pressure, and the air pressure gauges
  • After pressing down on the gas pedal, bring it down to idling speed and wait for the engine to pick up speed.

Stopping the car

The following steps need to be followed to bring the car to a stop:

  • Check all the mirrors and adjust them according to the driver’s position, to avoid people and other cars while driving.
  • Signal your intention to stop the car
  • Take the right foot off the gas pedal gradually and avoid jerky movements
  • Push the brake pedal down by gradually increasing the gas pressure
  • Just before the car stops, push the clutch pedal down fully, or else the engine will stop running in case it is not done properly
  • Right before the car stops, it is advisable to ease the pressure on the brake pedal as the car must be allowed to roll free for the last few centimeters before coming to a stop
  • Next, apply the hand brake and shift the gear to neutral in case of manual transmission or parked mode in case of automatic transmission
  • Take both feet off the pedals 
  • Finally switch the engine off 

Maintaining motion

These are the following steps to be followed for maintaining constant motion in the car:

  • First, ensure that the clutch pedal is depressed fully
  • Move the gear to first gear slowly and return the hands on the steering
  • Release the clutch pedal gradually till the car feels confused to move forward. Hold the clutch at that point
  • Give the signal for moving out
  • Check all the mirrors for incoming traffic from behind
  • Take a quick glance over the right shoulder
  • Keep both hands on the steering wheel and look ahead
  • Keep the left foot off the clutch pedal and on the floor
  • Let the car move in a steady manner for a few meters to feel up the gas pedal

How to start a car engine in cold weather?

These are the following tips that must be followed to ensure the car can start properly during cold weather:

  • Turning off all electrically operated components like the heater, defroster, windshield, headlights, etc.
  • Turn the ignition and hold it to allow the engine to crank for no more than 10 seconds to warm up the engine.
  • The above step is to be repeated and if it fails, it is advisable to warm up the battery separately before trying again.
  • If none of the above steps work, another fix includes jumping the battery.

Research has shown the various reasons why a car engine may face difficulties or might not even start.


This blog post addressed the question, ‘How does a car engine start?’.

We discussed a step-by-step guide on how to start and stop a car engine and how to maintain car motion. Furthermore, the ways in which a car can be started in the cold weather have also been discussed. Please feel free to comment on the content or ask any questions in the comments section below.

Frequently Asked Questions (FAQs): How does a car engine start?

What are the components involved in starting a car?

The components that play a crucial role in starting a car are the car battery, the car starter motor, the fuel pump, and the flywheel.

What are the things an engine needs to run?

A typical car engine needs three vital entities to help bring it in motion. They are the fuel that undergoes combustion, the presence of oxygen that helps support the combustion, and a source of ignition to initiate the combustion process.

Why do you have to put the clutch down when starting a car?

The clutch pedal needs to be released as the gear is shifted from neutral to first to avoid an accidental starting of the car while shifting gears, the clutch basically cuts off the linkage between the engine and the transmission lines to stop the power flow and is a safety feature.