What Causes the Starter Not to Turn When the Engine is Hot?

[SanCamilla]

The reasons why the starter does not turn when the engine is hot are: 1. The pull-in coil of the electromagnetic switch; 2. The holding coil, after its temperature rises, may short-circuit or ground due to decreased insulation performance. If the starter does not turn when the engine is in a hot state, you can wait for the engine to cool down and restart it. If the starter operates normally, it indicates a fault in the electromagnetic switch, which should be replaced promptly. The function of the starter is to convert electrical energy into kinetic energy when the key is turned to the start position, thereby starting the engine. Its role is to push the gear forward, engaging the starter's gear with the engine's flywheel. The large cylindrical component at the bottom is the starter motor, which provides the torque needed to start the engine.

[Gonzalez]

Hey, when it comes to hot starts failing, I've got a thing or two to say. I've run into this several times, mostly due to battery issues—chemical reactions slow down in high temperatures, causing voltage to drop quickly. Especially with older car batteries that have been used for a while, you might hear a few whirring sounds but no turnover on a hot day after parking. It could also be components in the starter motor expanding from heat and getting stuck, or poor heat dissipation leaving it rigid. My advice is to regularly monitor battery health and clean the terminals to prevent corrosion. If it happens, try waiting about 10 minutes for the car to cool down before attempting again—don’t force the key and risk damaging the motor. In severe cases, check the relay; burnt relay contacts or loose wiring can also cause trouble. Maintenance is key—don’t wait until you need a tow truck to regret it.

[RiverDella]

Last summer when I went out for a drive, my car wouldn't start after getting hot, and I was extremely anxious. Later, the mechanic told me that the problem could be due to an aging battery with poor performance in high temperatures, or the starter motor's internal components expanding and jamming due to heat. A simple solution is to wait a bit longer in the parking lot for it to cool down, or gently tap the starter motor casing to try and loosen it. I also learned that a faulty relay could be the culprit since it controls the current flow. For daily prevention, regularly replacing the battery and checking if the wiring connections are secure can save a lot of hassle. Road safety is not something to take lightly; if you break down on the road, turn on your hazard lights and pull over safely.

[Maureen]

Hot start failures are quite common, and I've studied them. The main issue is that the battery's discharge capacity weakens under high temperatures, leading to insufficient voltage for starting. Additionally, starter components like carbon brushes can expand when heated, getting stuck and unable to move. It's recommended that car owners check the battery's condition and use simple tools to test the voltage. Ensure the connections are clean and tight, as corrosion increases resistance and hinders current flow. Relays can fail for the same reason, potentially preventing signal transmission. For maintenance, keep the cooling system functioning properly and regularly clean engine compartment dust for heat dissipation. These small habits can extend lifespan and prevent unexpected failures.