What are the reasons for the engine not turning?

[MacCharlie]

The reasons for the engine not turning are: 1. The battery is dead or has weak power; 2. Loose or fallen wires causing switch or solenoid switch failure; 3. Worn brushes, misaligned brush surfaces, weak springs, or poor commutator contact; 4. Short circuits or open circuits in the field coil or armature coil; 5. Dirty commutator or protruding segments causing poor brush-to-commutator contact. Methods to check why the engine is not turning: 1. Inspect the starting circuit, fuses, relays, battery and connections, and the starter switch; 2. Check if the gearshift lever is in the P or N position; 3. Check the battery voltage and connections; 4. Inspect the operation of the starter's pull-in coil and hold-in coil; 5. Check if the engine's crankshaft is seized.

[VonHeidi]

I've experienced the engine not starting quite a few times, with the most common root cause being battery-related issues. For instance, a weak battery due to discharge often results in sluggish starts, usually caused by forgetting to turn off electrical devices after parking or prolonged inactivity. Corroded or loose battery terminals are another frequently overlooked issue – I've seen many cars face major troubles because of this minor problem. The starting system shouldn't be underestimated either; an aging starter motor or faulty relay can interrupt current flow, leaving you with complete silence when attempting to start. Ignition system failures like excessive spark plug carbon buildup or coil malfunctions prevent engine combustion – I once had a burned-out coil that left my car completely unresponsive. Other possibilities include fuel pump failure or activated anti-theft locks immobilizing the engine. The key takeaway: don't force it when this happens. First do a quick check for abnormal dashboard warning lights, then seek professional repair to prevent accidents.

[StBlakely]

Hey, the engine won't start? Don't panic just yet. I think the first thing to check is the battery—it's very likely just a low charge. Last week, I stupidly left the interior light on overnight. Loose connections are also common; gently wiggle the terminals to see if there's poor contact. Fuel issues aren't rare either—an empty tank or a faulty fuel pump. This time, I only remembered to check the pump after filling up the tank. In cold weather, the oil thickens and makes starting difficult—I've experienced this firsthand; the cranking sound isn't even loud in winter. If the starter motor makes unusual noises like clicking but doesn't engage, it might be jammed internally. A little maintenance tip: keeping the fuel tank full and the battery clean can reduce such incidents. If all else fails, just call a mechanic—simple and efficient.

[LydiaRose]

Failure to start the engine is usually caused by issues in the starting system. I believe the most common problems are worn starter motor gears or burnt relay contacts, which can prevent current from passing. Ignition components like expired spark plugs or failed ignition coils can also prevent the engine from starting—I once encountered a burnt coil during my DIY repairs and replacing it solved the issue. Additionally, a clogged air filter restricting airflow or a dirty fuel filter causing insufficient fuel supply should be checked. Occasionally, a malfunctioning Engine Control Unit (ECU) making incorrect judgments can also be the culprit. Using an OBD tool for timely detection saves both time and effort.

[MacHenry]

When the engine won't start, I always remind friends to check the fuel system first. The fuel pump might be faulty and not supplying fuel, similar to my colleague's car last year which cost a lot to fix this issue. Aging components in the ignition system like spark plugs need regular replacement to prevent problems. Oxidized battery terminals can be easily cleaned with vinegar. If the starter motor is faulty, it'll make a whirring sound but won't turn over. Relay replacement isn't difficult but better left to professionals. From a safety perspective, don't ignore that excessive cranking attempts can damage components. For manual transmission vehicles, push-starting can be an emergency method to protect the engine. Maintain regular maintenance habits like oil changes and air filter cleaning for prevention.