8 Common Reasons Why a Car Won't Start

"Diagnosing Car Won't Start Problems Quickly"

When your car won't start, it can be a frustrating experience. There are many possible reasons why your car won't start, but some are more common than others.

In this article, we'll explore eight common reasons why a car won't start and what you can do to fix them.

Watch our video that accompanies this article for diagnosing non start problems.
  1. Dead Battery

A dead battery is the most common cause of a car not starting. If the battery is too low on power, it won't be able to provide enough juice to start the engine.

To check the battery, use a voltmeter to measure the voltage. The voltage should be between 12.6 and 13.5 volts. If the voltage is below 12 volts, the battery needs to be charged or replaced.

  1. Bad Starter

The starter is the part of the car that turns the engine over. If the starter is bad, it won't be able to start the engine. To check the starter, connect a jumper cable from the positive terminal of the battery to the positive terminal of the starter.

If the starter motor engages and the engine turns over, the starter is working properly. If the starter motor does not engage, the starter needs to be replaced.

  1. Bad Spark Plugs

Spark plugs ignite the fuel in the engine. If the spark plugs are bad, they won't be able to ignite the fuel, and the engine won't start.

To check the spark plugs, remove them from the engine and visually inspect them. The electrodes should be clean and free of corrosion. If the electrodes are dirty or corroded, the spark plugs need to be cleaned or replaced.

  1. Bad Fuel Pump

The fuel pump is the part of the car that pumps fuel from the tank to the engine. If the fuel pump is bad, it won't be able to pump fuel to the engine, and the engine won't start.

  1. Clogged Fuel Filter

The fuel filter filters the fuel before it goes to the engine. If the fuel filter is clogged, it will restrict the flow of fuel to the engine, and the engine won't start.

To check the fuel filter, locate it under the hood and inspect it for signs of clogging. If the filter is clogged, it needs to be replaced.

  1. Low Fuel Level

If the fuel level in the tank is too low, the engine won't start.

  1. Engine Misfire

An engine misfire is when one or more of the cylinders in the engine are not firing properly. This can cause the engine to run rough or not start at all.

  1. Engine Timing Issue

The engine timing is the precise timing of the ignition and fuel delivery to the engine. If the engine timing is off, it can cause the engine to not start or run rough.

The timing belt or chain ensures that the valves in the engine open and close at the correct time. If the timing belt or chain is broken or stretched, the engine will not start or will misfire and stall.

Quick Facts & Things to Check.

There are many reasons why a car won't start, but the most common causes are a dead battery, bad starter, bad spark plugs, bad fuel pump, clogged fuel filter, low fuel level, engine misfire, and engine timing issue.

By knowing the common causes, you can quickly diagnose and fix the problem yourself, or seek the help of a mechanic if necessary, and knowing the potential cause can save you from being ripped off.

Remember to perform regular maintenance on your car to prevent these problems from occurring in the first place.

There are many possible reasons why a gasoline engine might not start. Some of the most common causes include:

  • Dead battery: A dead battery is the most common cause of a car not starting. If the battery is too low on power, it won't be able to provide enough juice to start the engine.

    A dead or weak battery is the most common cause of starting problems. To check the battery, use a voltmeter to measure the voltage.

    The voltage should be between 12.6 and 13.5 volts. If the voltage is below 12 volts, the battery needs to be charged or replaced.
  • Bad starter: The starter is the part of the car that turns the engine over. If the starter is bad, it won't be able to start the engine. The starter is the electrical device that turns the engine over.

    To check the starter, connect a jumper cable from the positive terminal of the battery to the positive terminal of the starter.

    If the starter motor engages and the engine turns over, the starter is working properly. If the starter motor does not engage, the starter needs to be replaced.
  • Bad spark plugs: Spark plugs ignite the fuel in the engine. If the spark plugs are bad, they won't be able to ignite the fuel, and the engine won't start.

    To check the spark plugs, remove them from the engine and visually inspect them. The electrodes should be clean and free of corrosion. If the electrodes are dirty or corroded, the spark plugs need to be cleaned or replaced.
  • Bad fuel pump: The fuel pump is the part of the car that pumps fuel from the tank to the engine. If the fuel pump is bad, it won't be able to pump fuel to the engine, and the engine won't start.
  • Clogged fuel filter: 
    The fuel filter filters the fuel before it goes to the engine. If the fuel filter is clogged, it will restrict the flow of fuel to the engine, and the engine won't start.

    A clogged fuel filter can restrict the flow of fuel to the engine, preventing it from starting. To check the fuel filter, locate it under the hood and inspect it for signs of clogging. If the filter is clogged, it needs to be replaced.
  • Low fuel level: If the fuel level in the tank is too low, the engine won't start.
  • Engine misfire: An engine misfire is when one or more of the cylinders in the engine are not firing properly. This can cause the engine to run rough or not start at all.
  • Engine timing issue: The engine timing is the precise timing of the ignition and fuel delivery to the engine. If the engine timing is off, it can cause the engine to not start or run rough.

    The timing belt or chain ensures that the valves in the engine open and close at the correct time. If the timing belt or chain is broken, the engine will not start.
  • Engine mechanical problems: There are a number of other mechanical problems that can cause a car not to start.

    These problems can include a blown head gasket, a cracked engine block, or a seized engine.
  • Check the engine computer. The engine computer controls the operation of the engine. If the engine computer is faulty, the engine may not start.

What should you check first?

If your car is not starting, the first thing you should do is check the battery. If the battery is dead, you will need to jump start the car or replace the battery. If the battery is not the problem, you should move on to the more complex causes of the problem.

Here are some additional tips for diagnosing starting problems:

  • Listen to the engine when you try to start it. If you hear a clicking noise, it could be a sign that the starter is bad.
  • Check the spark plugs. If the spark plugs are wet or fouled, it could be a sign that they are bad.
  • Check the fuel filter. If the fuel filter is clogged, it could be restricting the flow of fuel to the engine.
  • Check the fuel level. If the fuel level in the tank is too low, the engine won't start.
  • Have a mechanic diagnose the problem if you are not sure what is causing the car not to start.

starting with the most common ones:

  1. Check the battery. 
  2. Check the fuel level. 
  3. Check the fuel filter. 
  4. Check the spark plugs. 
  5. Check the ignition coil. 
  6. Check the starter motor. 

If you have checked all of the above and the engine still will not start, it is possible that there is a more serious problem with the engine. In this case, it is best to take the car to a mechanic for further diagnosis.

We hope this article has been useful to you and a good aid in diagnosing your starting problems, please feel free to comment below if you feel we've missed something or you are still having problems and hopefully we can get you the answers you need.

Be sure to join our friendly forums an join in with our community of like minded car enthusiasts.

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