Car Shuts Off While Driving: Causes, What to Do

A car that unexpectedly stalls while driving is stressful. The situation can also be dangerous—especially if you’re traveling on a busy roadway. It goes without saying that you’ll want to figure out why your car died and address the issue right away.

What Would Cause a Car to Shut Off While Driving? 4 Common Causes

Unfortunately, there isn’t a one-size-fits-all answer as to why your car might stall while driving. To figure out the root cause of the problem, you (or your mechanic) will need to do some troubleshooting.

You’ll typically find one of the following issues to be the root cause of the concern:

Ignition System Problems

Your car’s ignition system is responsible for creating the spark that ignites the air-fuel mixture inside the engine. The resulting series of explosions create the energy needed to propel your car down the road. Without the spark from the ignition system, the vehicle won’t run.

As you might guess, ignition system problems can cause your vehicle to stall while driving. The issue is typically caused by an ignition system component that affects all of the engine’s cylinders, such as a faulty crankshaft position sensor, rather than a component that affects just one cylinder (e.g., a bad spark plug).

Another ignition-related component that commonly causes engine stalling is the ignition switch. When your car’s key is in the “run” position, the ignition switch provides a pathway for electricity to travel from the battery to the engine management components, such as the fuel injectors and ignition coil(s). If the switch doesn’t make good contact, the engine will stall.

Fuel Delivery Issues

There are a variety of different fuel system designs in use today. However, a typical, port-injected fuel system uses a low-pressure pump to deliver fuel from the tank to the fuel injectors at the engine.

A lack of fuel pressure or fuel volume can easily lead to engine stalling. Common culprits include a faulty fuel pump or fuel pump relay. A clogged fuel filter or bad fuel pressure regulator is also common on return-type fuel systems.

Another often overlooked problem is the vehicle simply being out of fuel. Sometimes the fuel gauge breaks or is inaccurate. As a result, you don’t know you’re out of fuel until the engine stops running.

Battery and Charging System Problems

The battery and the charging system are responsible for providing power to all of your car’s electronics, including the components that keep the engine running (computer, fuel injectors, etc.). Something as simple as a loose battery cable can rob the entire vehicle of electrical energy, causing the engine to stall. Alternator overcharging or undercharging can also result in a vehicle that stops running while driving.

If your car battery died while you were driving, then it’s a sure sign that your vehicle’s alternator isn’t working to recharge the battery.

Internal Engine Failure

Without a doubt, the worst-case scenario is a car that dies due to an internal engine failure. When the engine fails, there’s a good chance you’ll hear some unnerving noises (rattling, knocking, etc.) right before the vehicle stalls. In many cases, a car that dies due to an internal engine failure will not restart.

Car Shuts Off While Driving FAQ

What should I do when the car shuts off while driving?

If you find yourself in a situation where the engine stalls while driving, the first thing you’ll want to do is guide the vehicle to the side of the road. Next, pop the hood and make sure the engine oil level is okay. Do not try to restart the car if there’s no oil on the dipstick or the engine was making strange noises before stalling. If everything looks okay, you can then try to restart the car. Call roadside assistance for a tow if your vehicle doesn’t restart.

Is a Car That Turns Off While Driving Safe?

Whether or not it’s safe to drive a vehicle when it’s intermittently stalling will depend on the vehicle’s hidden issues and the environment. If you suspect that there’s a problem with the vehicle’s fuel pump, then you shouldn’t continue driving in a remote location because you might end up stranded.

How do I dix a car that shuts off while driving?

As was mentioned, there are many different issues that could cause your car to die while driving. You (or your mechanic) will need to do some troubleshooting to determine the root cause of the problem.

Can a Bad Catalytic Converter Cause a Car to Shut Off?

A clogged catalytic converter causes increased back pressure in the exhaust. This stresses the engine and can cause it to stall. If your car starts fine, but eventually sputters or stalls, then your vehicle’s catalytic converter could be clogged.

How do I diagnose a car that shuts off while driving?

Diagnosing a car that stalls while driving can be difficult. Professionals often use their years of experience to narrow down the list of possible causes.

The video below provides one example of diagnosing and repairing a car that stalls while driving (due to a faulty sensor):

Where to Get Parts if Your Cat Shuts Off While Driving

Unexpected stalling is a very dangerous problem to have while driving your vehicle. The last thing you want is to stop without warning in the middle of a busy highway. Get a trusted mechanic to identify the problem as soon as possible. Once they find out which parts you need to have repaired or replaced, you can browse CarParts.com to find many of the pieces you need.

CarParts.com has a large catalog of aftermarket parts, all available at different price points to suit your budget. We guarantee the fit for any part you order when you use the built-in vehicle selector on our site. Our 60-day return policy lets you buy with confidence, and the easy-to-navigate website is there to make placing your order a breeze.

Whether it’s the crankshaft position sensor or a different faulty part behind your vehicle’s sudden stalling problems, we have you covered. Order your parts on CarParts.com today.