Why Does My Car Shut Off While Driving? Here’s Why

Does your car turn off while you are driving for some reason? Perhaps when you come to a stop? Here's why it happens and how to fix it.

Having your car shut off in the middle of a drive can be a horrible and potentially dangerous experience.

The engine consists of many parts which rely on multiple systems and sensors to work properly.

In most cases, a fault in either of these parts or sensors will not make the car shut off when driving but it is possible.

The potential causes are plenty and include being out of fuel, fuel pump problems, camshaft problems, and much more.

Further down in this article we will list the most common causes as well as how you can solve them.

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Why The Car Shuts Off Suddenly

There are multiple reasons why a car can shut off and accordingly behave differently depending on the cause.

For example, if the ignition is loose, many times, the car can be started again if the ignition switch is put in place again. On the other hand, a car with no fuel will not start until you add fuel to the tank.

Below you will find multiple potential reasons for why the car may shut down while driving. Every cause can be solved but may differ in complexity which will be discussed.

It is important to note that a car with an internal combustion engine will not have power steering or braking, making the car more difficult to control.

We will touch upon this at the end of this article, make sure to read through it as it can help immensely if the car suddenly shuts off.

Let’s get going!

Out Of Fuel

Fuel gauge

Probably one of the most common reasons why a car shuts down while driving.

Sometimes the cause may be due to a fuel leak, while other times the driver is to blame for not filling up the gas tank.

In other cases, the fuel gauge may be faulty and simply inaccurate.

Whatever the reason the fact is that a car with no fuel will not run, and it will shut down regardless of wherever you are.

In most cars, the fuel light will turn on when there is about 10% fuel left, which should be the first warning that you should fill up your fuel tank.

When there is no fuel left, there will not be any obvious warnings except that the car will start sputtering a second or two before you notice that stepping on the gas pedal will not do anything.

Consequently, the car will start to deaccelerate, and you will have to act fast to move the car to a place with less traffic.

When you are in a safe spot, all you have to do is fill up the fuel tank again. Make sure to have enough fuel to get to the nearest gas station and fill up the tank.

Bad Ignition Switch

Car Ignition Switch

Another potential culprit may be the ignition switch.

When the car key is turned, the ignition switch is turned as well, which then activates the electrical systems and delivers power to the ignition system.

Without an ignition system, there will not be any combustion and hence the engine will stall.

Sometimes, it is possible to simply turn the key again and the car will start again. If this is the case, you should look to stop somewhere safe and solve the problem.

Faulty Alternator

Modern Car Alternator and Engine

The alternator is what makes all the electronic accessories work in a car, this includes the ignition coil and consequently the spark plugs.

The good thing is that a bad alternator will generally show symptoms long before it gets so bad that the engine stalls while driving.

Some symptoms include dimmed lights, flickering lights, a dead battery, and more.

A car with an alternator that is not functioning will not start again, which means that you need assistance to move the car.

Related:Signs Of A Bad Alternator

Bad Fuel Pump/Filter

Fuel filter

As we have previously explained a car with an internal combustion engine cannot run without fuel.

There may be more than enough fuel in the tank, but not enough fuel coming into the combustion chamber.

The reason for this may be due to a bad fuel pump or a bad fuel filter.

The job of the fuel filter is to catch dirty particles and other particles that should not reach the combustion chamber and the fuel lines.

Just like any type of filter, it must be changed, if it does not it can be clogged, and no fuel will be able to pass.

Logically, if no fuel can be passed from the fuel tank to the combustion chamber, no power can be produced, and hence, the engine will shut down.

Similarly, a fuel pump pushes the fuel from the fuel tank. Without a pump, there is nothing to push the fuel into the combustion chamber which means that the engine will shut off.

Just like an alternator, in most cases, a bad fuel pump or filter will show symptoms before they turn bad to the extent that it shuts down the engine.

In both cases, each respective part must be replaced to keep going.

Related:Symptoms Of A Bad Or Clogged Fuel Filter

Faulty Crankshaft Position Sensor

The crankshaft plays a vital part to make the pistons move properly and provide rotational power to the wheels.

Because the crankshaft must be in sync with all the other parts and processes, a crankshaft position sensor sends the information to the ECU which makes everything synchronized.

If it turns out that the process is desynchronized, misfires will happen, and in severe cases, the engine will stall.

In most cases, you will not be able to come to speed with a faulty crankshaft position sensor unless the sensor abruptly breaks.

This is because the symptoms of a faulty crankshaft position sensor will in most cases be noticed when you start the car or when you are just about to move.

A bad crankshaft position sensor must be replaced. This means that you should not try to drive anywhere with a bad crankshaft position sensor.

What Should You Do If The Car Shuts Off While Driving?

Young couple after a car breakdown at the side of the road

Regardless of the reason why the engine shuts down while driving, knowing what to do if it happens can be vital to protect you and others on the road.

When the engine shuts down the car will behave differently as there is no power steering and it will be tougher to break.

The most important thing is to keep calm. While it is easy to say that when you are not in that situation, it is worth mentioning as it will help in your decision-making and execution.

Make sure to steer the car to the side of the road, provided it is safe to do so. If the electronics still work, turn on your hazard lights.

The steering will still work but offer a greater resistance, which is also true for the brakes. If you find it hard to brake, you may use the emergency brake, however, be very cautious if you do. 

Pulling the emergency brake recklessly will often result in total loss of control, potentially crashing it.

Instead, you should lift the emergency brake slowly and steadily until the car stops. When you have come to a stop, you should safely leave the car and wait for help to arrive in a safe(er) spot.

Conquer Driving on YouTube has a great video about e-braking and covers both automatic and manual transmissions, as well as traditional and electronic emergency brakes.

Summary

There may be several reasons why an engine suddenly stops. Some include an empty fuel tank, a faulty crankshaft sensor, or a faulty alternator.

Whatever may be the cause, it is important to not panic and move to the side of the road safely if it happens.

A car without a working engine will not have power steering, this means that it will be much harder to rotate the wheel. This also applies to the brakes of the car.

Luckily, an engine shutting down while driving is a rare occurrence, but they do happen.

In most cases, there will be different signs and symptoms that will hint that there is a problem with a car component.

Unless you have run out of fuel, you will need to replace the affected part that made your engine shut down.

As with almost any car-related problem, many problems can be avoided by maintaining the car regularly and effectively according to the manufacturer’s recommendation.

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Bajro Muric

Bajro is a big car enthusiast with a love for writing and teaching. He writes about anything regarding cars - from common problems and fixes to racing.