What to do if your car shuts off while driving.

First, Don’t Panic!

Hopefully, these friendly words of advice will help you on road trips as well as intergalactic travel.

If your car suddenly dies, get it to a safe place, take a deep breath, and try to think about how the car was acting the last 30 seconds before it stopped running, then think about if the car behaved unusually in the days leading up to that point while at idle, high RPM, or under load. Was your car trying to tell you anything? Most of the time, your car will give some signs of what went wrong if you know how to interpret them.

Let’s look at the signs we are given and how we can translate that into possible reasons your car stopped running.

Did the car have any surges, lags, misfires, stutters, hiccups, bangs, or did it just die?

Power surges and lags

Powers surges and lags are often caused by poor fuel delivery. If you are low on gas the fuel will slosh onto and off of the fuel pump until it is finally empty and dies. If the fuel pump itself is failing, it will likely lose pressure at high RPM or under load. Another symptom is it will likely start to make whirring or whining noises but that might only be audible from the backseat or close to the gas tank.

Occasional misfires

Occasional misfires are likely caused by ignition problems. This could be a fouled spark plug, a bad coil plug/distributor, or a loose connection between them.

Running consistently rough

Running consistently rough with poor fuel consumption is likely a symptom of the sensors that detect airflow or oxygen malfunctioning. When the car is receiving incorrect information about the amount of air it needs, it will miscalculate fuel, timing, and ignition. Depending on the sensor malfunction and the CPU feedback loop it affects, this could be a continuous issue, or it may only affect a certain RPM range.

Clattering and bangs

Clattering and bangs usually indicate a more serious mechanical issue that likely needs professional diagnosis. In many cases, your car could have a blown engine.

Dying suddenly

Dying suddenly with no warning symptoms tends to indicate electrical issues like bad alternator. , short circuit, or broken connections.

Are there any extra warning lights?

Modern cars have a lot of lights for almost every problem under the sun but there are only a few capable of causing a car to shut off while driving. If there is a check engine light on, have a mechanic read the codes as they will likely provide the location of the failure. Look out especially for ones that look like a battery, thermometer or oil can, as they indicate serious problems?

With the symptoms identified, let’s look at the issues that could be causing them.

Fundamentally, a car needs three things to run. Gas, Air, and Spark to ignite the mixture of the two. If it suddenly dies while running, then one or more of these things stopped working.