9 reasons the engine cranks & turns over, but the car won’t start

There are many reasons why the engine cranks and turns over, but the car won’t start. It could mean that the engine is having difficulties producing the spark, getting fuel, or creating compression. They are all essential to start the car.

The most common causes are related to the fuel system or the ignition. A bad ignition coil and a clogged fuel filter will make it impossible for your car to start. The source might also be mechanical, where some faulty components might cause your problem.

When the car or truck cranks but does not start, it generally means there is a problem with the starter. There are five things necessary for the combustion reaction to take place. They are fuel, air, spark, compression, and timing.

car engine

If the problem in your car is serious, it might represent a risk for you and the other drivers on the road. You want to avoid scenarios where your car died while driving or the problem is making driving harder for you. 

If you are still confused about this problem, we will analyze it and provide solutions for you. Below, we will look closely at 9 reasons why the engine cranks and turns over, but your car won’t start.

Why does my engine turn over & crank but not start?

There are several reasons your engine turns over and cranks, but the car won’t start. We will look at the most common 9 symptoms to know which one applies to you.

  1. Bad ignition coils
ignition coils

The ignition coil can be considered the heart of your car’s ignition system. Each cylinder has a coil, and they are responsible for transferring the energy from the battery to the spark plugs. As a result, the fuel mixture is ignited. 

When you turn the car in the ignition, a low voltage current passes the ignition coil. It is then amplified to deliver the necessary energy for the spark plugs to jump the gap. But if these coils fail, a weak spark will be generated. 

When such an ignition coil goes bad, the engine will misfire. However, it can also fail without any specific warning signs. If these ignition coils are separated, the car won’t start if two or more go bad.

  1. The spark plugs are worn.
spark plugs

A powerful spark is essential for proper ignition of the fuel. These plugs are supplied with a high voltage from the ignition system. This voltage is carried through the wires to produce the spark that will light up the fuel mixture.

If these spark plugs are worn out, the current will not be able to jump the gap between the terminals. A weak spark will be generated, but it is not enough to start the car. 

Usually, spark plugs are very durable and need replacement once every 50,000 miles. Some special spark plugs are manufactured from platinum and iridium. It can last as long as 150,000 miles before needing replacement.

  1. Malfunctioning MAF sensor
MAF sensor

MAF stands for mass airflow sensor, which calculates the total amount of air coming into the engine. It sends the information to the central computer to adjust the fuel injection. 

If this sensor sends the wrong signals, fuel ratios will be miscalculated. As a result, the vehicle will run too rich or too lean. Most of the time, a car that cranks but doesn’t start results from a lean mixture.

If an inaccurate air flow causes the engine to run rich, it can make the unburnt fuel escape the system and allow carbon to build up on the spark plugs. As a result, the spark plugs will fail.

  1. Clogged air filter

As the amount of air increases, the amount of fuel that goes into the engine is affected directly. The computer will lower the amount of fuel if there is a restriction in the airflow. The air filter ensures the air is clean and free of debris.

It catches the dust and dirt that might be in the air when it comes through. But over time, this filter will constantly attract dust and particles. It makes it dirty. Sometimes, it can ever get blocked by a big piece of debris.

As a result, the engine computer will adjust the fuel ratio accordingly. It forces your engine to operate at lower power. The engine will crank, but it will fail to start as it doesn’t have sufficient power. 

  1. A malfunctioning throttle position sensor

Certain sensors can affect the amount of fuel that gets in, even if they are not part of the fuel system. Sometimes, this sensor will create a condition that won’t allow the injectors to fire fuel. 

When the throttle position sensor malfunctions, it can send a wrong signal to the computer. It will incorrectly interpret that the throttle is wide open. It puts the vehicle in flood mode, preventing fuel injectors from firing.

In this case, the engine won’t get any fuel injection. It produces long cranks but won’t allow the car to start. The airflow can also be restricted by a bad throttle position sensor, which will create a similar problem.

  1. Bad fuel filter
ford fuel filter

If the filter is clogged, it will have the same effect as a bad fuel pump. If you have low fuel pressures, this can create an overlapping factor. As a result, the fuel sent by the pump has to go through a filter to screen out the contaminants before it enters the cylinder. 

The filter will ensure the circulation of clean fuel without altering its movement. But if the filter is dirty or full of stuck debris, it can cause a reduction in the fuel supply which will eventually lead to your car not starting. 

The pump can also burn up if the filter is clogged. It happens because of the pressure created by the lingering fuel. It is often recommended to replace the fuel filter once every 20,000 miles to avoid such a situation. 

  1. Bad fuel injectors
fuel injectors in a box

The fuel injectors are responsible for bringing the fuel into the cylinders. These injectors are meant to use the fuel with precise timing while following a strict process. But since they are so complex, they need perfect conditions to operate correctly.

A slight imperfection in fuel will cause issues that will generate several problems. If your car cranks without turning over, the fuel injectors can be considered as a possible cause. If the fuel is not filtered, it can lead to blockages.

A bad or dirty fuel injector will restrict the fuel that goes into the cylinders and further reduce the power your car needs to start. The same condition can occur if the fuel injectors are stuck close or don’t function properly. 

  1. Fuel

A sufficient and consistent fuel flow is necessary to start the engine. If insufficient fuel goes into the cylinders, there will be a loss of power, and the engine will fail to start. A quick way to check if there is a restriction in fuel is by using starting fluid.

Spray this fluid on the air intake or in the air filter and start the car again. Suppose your vehicle runs for a short time before shutting back down. In that case, it is enough confirmation that fuel delivery has a problem. 

  1. Bad fuel pump
fuel pump

A bad fuel pump is the most common problem for a car that cranks but doesn’t start. The fuel travels through the system by pressure, and the electric motor rotates to generate and send a fuel stream.

A malfunctioning pump cannot create enough pressure to allow optimal fuel circulation. Therefore, it won’t be able to send a consistent stream to the engine. It causes a lack of fuel pressure. The pumps will last long and must only be replaced once every 100,000 miles. 

The best car diagnostics tool

Here is the best car diagnosis tool we could find after thoroughly searching the market. 

ANCEL AD310 Classic Enhanced Universal OBD II Scanner

It is one of the best-selling scanners on the market, which can easily determine the cause of your vehicle’s problems. It can read and clear trouble codes, collect vehicle information, and give you live data in real time. 

The 2.5-foot cable will let you easily operate this tool, which can even reach the tight spaces of the engine bay. Because it is made out of high-quality material, this tool is also very durable. It is important to have a strong scanner, especially when you use it in a garage.

This scanner will help you diagnose the problem. You will be able to understand it regardless if you are an expert mechanic or an amateur car enthusiast. The AD310 scanner supports all OBD2 protocols, which makes it efficient and practical. 

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ANCEL AD310 is a great diagnostics tool.

Car overheated, won’t start but turns over – what do I do?

After extensive research, we found the best product that comes as a solution to this problem.

Valvoline Extended Protection Full Synthetic Motor Oil

This oil has 10 times stronger thermal resistance than its competition, making it a valuable choice. A dual defense additive technology will provide the ultimate protection against wear. You won’t have to worry about things breaking down in your engine.

It is built for modern engines with a special formula that is optimized to withstand extreme conditions. Friction modifiers stop the moving parts from touching, therefore minimizing energy loss and keeping friction at a minimum. 

The starter works, but the engine won’t turn over.

If the starter works but the engine won’t turn over, there are several reasons why this could happen. But the most common source is the ignition or the fuel system. You should ensure enough fuel pressure and an ideal spark to turn your engine on.

A faulty sensor may also cause this problem. There are specific trouble codes that will signal this problem. You can identify them with the help of a car diagnostic tool. 

Car cranks but won’t start even with starting fluid.

While starting fuel can be a temporary solution, it should allow you to start the engine. However, there can be a few reasons your car doesn’t start. They include:

  • Bad fuel pump
  • Bad timing belt
  • Faulty spark plugs
  • Insufficient fuel
  • Malfunctioning ignition

Because it is not easy to tell what is causing this problem, you should take the car to the nearby auto shop and have a skilled mechanic look at it. 

Trouble starting the car after sitting overnight

If the car struggles to start early in the morning, the fuel pump or filter is likely a problem.

Bad fuel pump

The vehicle’s pressure system can be responsible for this problem. Modern cars need a highly pressurized system to get the fuel to the engine. If your battery and starter work fine but the car is not starting, there’s a good chance that the engine lost fuel pressure. 

Check the fuel pump and evaluate its condition. If this pump has failed, there is not enough pressure to get the fuel into the engine. 

Dirty fuel filter

It is another reason you might have trouble starting your car in the morning. The filter can get dirty or even clogged with debris that was stopped from reaching the engine. If this filter becomes too dirty, it will lower the pressure and prevent your car from starting. 

The car won’t start, but the lights come on.

car engine in good condition

If the lights come on the dashboard, but the car won’t start, you should consider starter engine issues. You can locate this starter under the hood of your car and directly check the source of the problem. The starter might be faulty if you don’t hear a clicking sound when you start the engine.

A broken or damaged ignition switch will prevent your car from starting, just like a bad starter. If the headlights turn on, but your car won’t start, it means the battery is charged. However, the ignition has a problem. 

FAQ

What sensors can cause a car not to start?

A discharged battery or a faulty starter can be why your car does not start. Additionally, there are other issues, such as specific sensors giving out incorrect readings. They are:
– brake pedal position sensor
– fuel pressure sensor
– crankshaft position sensor
– manifold absolute pressure sensor
– oil pressure sensor
– throttle position sensor
– mass air flow sensor

Can a bad battery cause a crank not to start?

A dead battery is a common cause of the car not starting. The starter may turn slowly if this battery is weak but not entirely dead. You will hear a specific sound when this happens, and it is a good indication that you should recharge the battery.

If the voltage drops even further, there is no sound generated. Jump-starting your car can be a temporary solution, but you should find the cause of a dead battery as soon as possible. 

Why won’t my car start but the radio and lights work?

If your car does not start, but the radio and lights work, there could be issues with the starter solenoid. The current passes through the coil when the electromagnet in the starter receives power from the battery. It affects the solenoid as a magnetic field is created.

If the starter solenoid is not working, you won’t hear a click. No power will be generated. But if the battery is charged, the electrical connection might still allow the lights and radio to turn on. 

Can an O2 sensor cause my car not to start?

The O2 sensor will not be a cause for your vehicle’s problem. The car will not start mostly because of a fuel pump or the ignition system problem. You should check the pressure of the fuel and have a look at the spark as well.

If you notice they are malfunctioning, you can narrow the problem down and get more specific with your solution. The ignition system might be at fault, or a sensor could give false readings. 

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