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As a car owner, you’re bound to get your fair share of automobile problems even if you follow the proper maintenance practices. Unfortunately, car problems can be tough to diagnose on your own. If your car won’t start and you aren’t sure what’s causing the problem, it is best to consult a mechanic. 

However, one of the most common car problems is when you turn the key and the engine doesn’t crank. We rely on our cars for many things, so it can be frustrating when your car refuses to start because the engine won’t crank. So, what causes your car engine not to crank? 

There are many possible reasons the engine doesn’t crank. Some are more common than others. In most cases, it’s either a dead car battery or corrosion. 

Dead car battery

An engine start button, which the engine won't start if not working properly.
Engine start and stop button | Getty Images

Your car battery provides the zap of electricity needed to bring the engine to life. If your car battery is not working, your car simply won’t start. A dead battery is the most common reason your engine doesn’t crank. 

Car batteries can last for years, but nothing lasts forever. The worst part about car batteries is that they always seem to fail at the most inconvenient times. Many factors can contribute to a dead car battery. Some of the most common causes of a dead car battery are: 

  • The headlights or dome lights were left on overnight or for a long time
  • A loose wire in your battery connections
  • The water inside your car battery has evaporated, leading to poor conductivity
  • A really old battery

What do you do if your car battery is dead? You can always try to jumpstart your car if you suspect a dead battery to be the culprit for a no-crank condition. But as mentioned earlier in the article, it’s best to have a mechanic inspect your car to rule out other potential issues. 

Car battery corrosion

If your car is having trouble starting, the problem could be car battery corrosion. As corrosion builds up, it can interfere with the battery’s ability to function. In addition to preventing your car from starting, car battery corrosion can damage your car’s electrical wiring and air conditioner lines. 

Battery corrosion appears as white, green, or blue-tinged powdery substance on your car’s battery terminals, posts, or cables. What causes car battery corrosion? AutoZone explains that corrosive gases or liquids from inside the battery escape and react with the metal contacts and battery terminals, causing them to corrode. 

If you have an old battery nearing the end of its useful life, you will start to see corrosion. This could be the reason your car engine won’t crank. Family Handyman says there’s not much you can do to prevent car battery corrosion. Check your battery frequently for signs of corrosion and clean it to avoid inconveniences.

When the car engine doesn’t crank, but the lights work

Sometimes the problem isn’t so obvious. You can try to narrow down the cause of the problem by turning on your headlights or dome light, Lifewire explains. If your car’s lights can turn on, but the engine won’t crank, it means that your battery is fine, but something else is preventing the crankshaft from turning. 

If you are positive that your car battery is working properly, but your car still won’t start after several tries, a bad ignition coil is a likely culprit. The ignition coil transforms the electrical energy from the car battery into an electric spark. If the ignition coil malfunctions and fails to deliver the required voltage to the spark plugs, your car won’t start. 


My Car Won’t Start, What’s Next?