Why won’t my car start?
We use our cars for countless tasks – from getting the groceries to taking the kids to school, from getting to and from work to visiting friends and going out of an evening and having a social life, your car is a pretty important tool.
Consequently, there are few more annoying things than that moment when you turn that ignition key, or push that ‘start’ button, and all that happens is . . . well, basically nothing. You might get a sputter or two as the engine tries to come to life, but you aren’t going anywhere.
For most of us, the cause of this malfunction is a mystery but there are a few candidates as to the cause.
1. Dead battery
The battery is one component that most car owners will have had to get replaced at some point. Its main function is to provide the jolt of power to the starter motor to get the car’s engine cranked up and moving (a common rating you’ll see associated with car batteries is CCA, or Cold Cranking Amps, which is the measurement of the current a fully charged battery can deliver). Basically, if the battery has lost its ability to deliver this jolt of energy it has, in effect, died and your car is going nowhere.
2. Faulty starter motor
An electric motor that is connected to the battery, the starter motor takes an initial burst of power from the battery to kickstart the engine and get it moving. The starter motor is connected to the car’s flywheel and, when engaged, causes the flywheel to spin and engage the engine components that suck air and fuel into the combustion chambers. At the same time, electric current is sent to the spark plugs which then ignites this fuel and air mixture. Once that initial combustion takes place, the engine is up and running and begins to run on its own.
3. Faulty ignition switch
The ignition switch activates the car’s main electrical systems. The switch has three positions: Off, On and Start. Assuming you start your car using a key, then you’ll know that turning the key one notch – to the ‘on’ position – won’t start the car but does power up the lights and other vehicle accessories. Turning one more notch to the ‘start’ position, initiates the full engine start-up process. The ignition switch can malfunction – contacts and other components within it can fail over time – and if it does, your car will have trouble starting.
4. Clogged fuel filter
A modern, fuel-injected engine needs clean petrol in precise amounts to be injected into the combustion chamber. Any dirt or particles that impede this flow of fuel will disrupt the engine’s ability to perform at its best. The fuel filter is designed to remove these particles. However, the filter itself can become choked with material and restrict that needed flow of fuel. This restriction of flow can lead to difficulty in starting the car, as well as misfires, stalling and a decrease in power when in motion.
5. Fuel pump malfunction
The fuel pump is responsible for supplying fuel from the fuel tank to the engine. If the pump is malfunctioning, fuel won’t reach the engine, or there’ll be problems with quantity and pressure that will lead to various problems. These will include engine sputtering, stalling, loss of power and trouble starting.
6. Spark plug failure
The spark plugs are the components responsible for creating the electric flash that ignites the fuel and air mixture in the engine’s combustion chambers. They are designed to spark at specific times and with specific power and when they start to malfunction a number of issues can arise. Worn out spark plugs will lead to poor performance and poor fuel economy as well as rough idling, engine misfires and, of course, can lead to the engine being hard to start.
Want to learn more?
MTA Queensland’s Vehicle Maintenance course is designed for those who are interested in gaining valuable information and learning good practices for everyday vehicle use. The result: a safer journey with fewer breakdowns and repairs. If you have ever wanted to learn how to carry out preventative maintenance, then this course is for you.
28 November 2019
Please note the information contained on this page is general in nature and does not take into account your specific needs or circumstances. You should consider whether the information is appropriate to your needs, and where appropriate, seek professional advice.