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Common Reasons Why Your Car Won’t Start

No matter how well you maintain your car, you’re bound to get in it one day and not be able to get the engine to start. What causes this, and what can you do to fix it?

Addressing the Most Common Problems

Nothing happens when you turn the key

There’s no electrical connection between the battery and the rest of the car. Make sure the battery is connected and the terminals aren’t corroded. The dash lights up, but nothing happens when you turn the key – There are safety switches that need to be engaged before the ignition will work. Make sure the shifter is in

A clicking noise can be heard when turning the key

The battery has some charge, but it’s not enough to power the starter. That clicking sound is the starter getting stuck because it doesn’t have the power to spin the crankshaft. Sometimes, the battery has enough charge to slowly turn over the motor before clicking. Cold weather reduces battery power and increases starting effort, making this more likely to happen in winter.

The engine cranks, but won’t start

There are two possible causes: a lack of fuel or a lack of spark. First, make sure there’s fuel in the tank, then check the connections between the spark plugs, spark plug wires, and the wiring harness or distributor. If there isn’t anything obvious, trace the lines from the fuel rails or carburetor to the firewall to check for fuel leaks. Old cars use a distributor to make the connection between the coil and the spark plug wires. If the engine won’t start after it has been raining, moisture may have made its way into the distributor cap, shorting the connection. Spraying a water displacer like WD-40 into the cap will remove this moisture.

Other Issues that Can Keep Your Engine from Starting

A broken fuse can keep the fuel or ignition system from being powered. There should be two fuse boxes: one under the hood, and a second under or in the driver’s side dash. Diagram stickers on the top of these boxes will list the function of each fuse.

The MAP or MAF sensor tells the engine how much air is entering the engine so it can add the correct amount of fuel. If the hose between the sensor, usually located next to the air box, and the intake manifold, bolted directly to the engine, is cracked or has a loose connection, the sensor reading will be incorrect and the engine won’t get enough fuel. A dirty or broken sensor can also cause a faulty reading.

If the ignition switch fails, turning the key won’t activate the starter. When turning the key to the run position, the dash should light up. If the battery and connections are good, turn on the headlights and then turn the key to the start position. If the ignition switch works, the lights should dim while power is being sent to the starter.

Corrosion or loose connections between the starter and the wiring harness can keep it from getting the electricity it needs to turn the engine over. Brushing off this corrosion and tightening down bolts should correct this. Disconnect the battery beforehand to keep yourself from being shocked.

Most starter failures are caused by a bad throwout bearing. This part pushes the starter gear out so it contacts the flywheel or flex plate and turns the motor. If you can hear the starter spinning but nothing happens, the entire unit should be replaced.

Newer cars use an electronic system to send spark to the plugs. Instead of using a distributor’s gear-driven system, a crank position sensor tells the ECU when to fire the spark plugs. If this sensor fails, the ECU thinks the crank isn’t spinning.

If a key-shaped light turns on when trying to start the car, the security system doesn’t recognize your key. Try a spare key and consult your owner’s manual on how to get the original key recognized again.

Need Body or Interior Work? Take Your Car to the Experts at Merton Auto Body

We might not do engine work, but if you need anything fixed on your car’s exterior or interior, or you want to get a custom paint job for your car or motorcycle, visit Merton Auto Body. We’re an I-CAR Gold Class certified repair shop, and our staff is ASE certified, so we’re able to use the latest techniques to repair your vehicle.