When a Car Won't Start

 

When a car won't start there is usually one key thing that you need to know.

"is it cranking or not?"Cranking is referred to as the "revving" noise that you hear  before an engine is started. If an engine is not cranking then you do not hear the engine trying to start. You would either hear a clicking noise, or no noise at all.

So let's look at the different things that could cause an engine "NOT" to crank, and instead cause a clicking noise or no noise at all.

If you try to start your car and you don't hear anything, or all you hear is a clicking noise, it could be a few things.

A bad battery - (the job of the battery is to supply voltage to sensors, actuators, and motors in the vehicle. In some rare cases a low battery will cause an engine to crank slowly, but 90% of the time a low battery will cause your car to make a clicking noise or cause a no crank no start condition)

A bad ignition switch - (the job of the ignition switch is to take the voltage from the battery and complete the circuit from the battery to the starter, thus cranking the engine over. A bad ignition switch will cause a no crank no start condition)

A bad starter - (the job of the starter is to take the voltage that has been supplied by the battery, through the ignition switch, through the neutral safety switch, and crank the engine over. A bad starter will cause a no crank no start condition)

A bad neutral safety switch - (the job of the neutral safety switch is to complete the circuit between the ignition switch and the starter. A bad neutral safety switch will cause a no crank no start condition)

3. A loose or bad connection to the starter

4. A loose or bad connection to the battery

5. An open fuse between the starter circuit


Now let's look at the things that would cause an engine to crank but not start.


If you try to start your car and you hear the engine cranking (revving or trying, but just not starting) it could be a few things. 

In order for a gas engine to start once it is cranking you need three things. 

Air/Compression, Fuel, and Spark. If you are missing one the engine will never start.

*No Air - or Compression (Lack of compression would cause an engine to crank but never start. Things that could cause lack of compression are:

- Timing belt or Timing chain broken and or out of time

- Internal engine damage, pistons, valve, head gasket etc.

- Clogged catalytic converter

No fuel 

(Lack of fuel would cause an engine to crank but never start. Things that could cause lack of fuel are:

- Bad fuel pump

- bad fuel injector

- open fuse or relay in fuel pump circuit

- No gas, or bad gas

- plugged fuel filter, or lines

2. *No spark (Lack of spark would cause an engine to crank but never start. Things that could cause lack of spark are:

- bad spark plug

- bad ignition coil, wires, or distributor

- Bad crank sensor, cam sensor or computer. (This could prevent spark and fuel when bad)


So next time your car doesn't start ask yourself. Is it cranking or not, and then take a look at this list.