Why won't the engine motor turn over?

[QuinnFitz]

Engine motor failure to turn over may be caused by malfunctions in the ignition system or fuel delivery system. The following details these causes: Fuel delivery malfunction: Clean the fuel filter screen and perform cleaning on the filtration components in the system, replacing them as needed. For ignition system issues, check whether spark plug carbon buildup is severe, whether ignition voltage is sufficient, and note that spark plugs have a service life - replacement is recommended upon reaching their usage cycle. Ignition malfunction: When the car won't start but the headlights function normally, this condition is mostly caused by open circuit in the motor excitation coil. Replacement of the motor magnetic switch is recommended.

[LeEmmett]

Last week, my neighbor's young guy had the exact same issue with his car—it just wouldn't start no matter what. I squatted beside him watching him struggle for a while and found that the most common culprit is still the battery: loose or corroded terminals covered in white powder. Pouring boiling water over them and tightening usually does the trick. If turning the key yields absolutely no sound, it's likely a faulty starter relay—this little square box in the fuse panel is toast if it rattles when shaken. Another possibility is the car key's anti-theft chip acting up; trying the spare key is the easiest fix. If all else fails, calling for roadside assistance is the way to go, letting the mechanic use a diagnostic tool to check wiring or starter brush wear. Older cars especially need attention for seized starter gears—a few taps with a wrench might just save the day.

[Alyssa]

Helped a colleague with this issue yesterday, sharing some practical tips: First, check the brightness of the dashboard lights—if the headlights are dimmer than usual, it's likely a weak battery. Then, listen for a clicking sound when turning the key; if present, there's an 80% chance the starter motor solenoid is faulty. Tapping the motor casing with a metal rod can sometimes provide an emergency start, but don't hit it too hard. You can also inspect the 15A starter fuse in the fuse box—replace it if blown. Use a voltmeter to measure the battery; it should read above 12V to meet the standard. If it's below 9V, it needs charging. For modified circuits, watch for leakage from added devices—leakage over 50mA can drain the battery overnight. A broken alternator belt can also cause sudden power loss, so check the belt's condition while you're at it.

[AdelineMarie]

Our driving school's training cars often encounter these issues. New students are most likely to forget turning off the headlights and drain the battery. Here are three self-rescue tips: when using jumper cables, don't mix up the positive and negative terminals; for manual transmission cars, try push-starting in third gear; pay attention to worn ignition switch contacts in older vehicles. During the rainy season, prevent the starter motor from short-circuiting due to water ingress. If the motor makes unusual noises after wading through water, get it repaired immediately. Cars with start-stop functions are especially hard on batteries, requiring more frequent checks every two years. Audio system modifications exceeding 2000 watts are particularly prone to burning out the main wiring. With the recent hot weather, the risk of spontaneous combustion is high. If you notice smoke from the wiring, cut off the power immediately.