What Causes the Abnormal Noise When Turning the Car Key?

[LaAbel]

There is an issue with the ignition switch. The rear part of the car key is connected to a circular circuit switch, which rotates when the key is turned to connect the circuit (sequentially activating the audio system, the entire vehicle circuit, and the starter motor). When the switch has poor contact, sparks occur along with a squeaking noise. The solution is to remove and replace or repair this switch. Related details are as follows: 1. When the ignition switch is in the "OFF" position: When the key is turned to the "OFF" position, the two contacts in the horizontal position are connected, which means the external wires "white-black wire" and "green wire" are connected. If you measure these two wires with an ohmmeter (Ω setting) at this time, they should show continuity. In the actual vehicle, the connection of these two wires indicates that the entire vehicle's electrical system is shut down, and the ignition system circuit is in a short-circuited state, causing the engine to stop. 2. When the ignition switch is in the "ON" position: When the key is turned to the "ON" position, the two contacts in the horizontal position are connected, which means the external wires "red wire" and "black wire" are connected. If you measure these two wires with an ohmmeter (Ω setting) at this time, they should also show continuity. In the actual vehicle, the connection of the red and black wires indicates that the signal system is activated, and the signal circuit is ready to operate at any time.

[DiCassidy]

There's a strange noise when turning the car key. I've encountered this situation a few times over the years of driving, and it's quite annoying. Common causes include the starter motor possibly aging, where the motor gear and flywheel make a screeching sound upon contact, or insufficient battery power causing abnormal motor rotation. In my case, it was a loose starter that squeaked every time I started the car, and later inspection revealed the screws weren't tightened properly. Issues with the relay in the ignition system can also cause abnormal sounds. If the noise becomes more frequent, it's really necessary to visit a repair shop promptly; otherwise, one day the car might suddenly fail to start, leaving you stranded on the road. When checking, pay attention to the source of the sound, but don't tinker blindly—professional diagnosis by a technician is more reliable, saving money and providing peace of mind. With cars, if details aren't handled properly, the entire driving experience can be ruined, and it might even shorten the lifespan of components.

[GenesisLee]

I'm always tinkering with cars, and when the key turns with a squeak, don't panic right away. Most likely, it's an issue with the starter motor—either gear wear or poor contact causing the noise; it could also be a weak battery, where unstable voltage during startup triggers the sound. You can do a quick check yourself: turn off the key and see if the headlights and radio work, and inspect the battery terminals for corrosion. If the battery is fine, check the wiring connections near the starter to ensure they're tight. Last time, I found a loose connection—tightened it up, and the noise improved. But if the sound persists, it's best to get professional help to prevent the problem from worsening and affecting the entire starting system. Always keep an eye on your car's condition, especially older ones—regular maintenance can prevent such issues, so don't let small problems turn into costly repairs.

[GemmaRose]

When you turn the key and hear a strange noise, I have to say it's quite dangerous, especially if you have kids at home. It could be the starter motor slipping or a relay malfunction, turning the starting sound into a grinding noise. The same thing happens when the battery is drained—you notice abnormal starting as soon as you get in the car. This affects normal vehicle use and can even make it difficult to drop the kids off at school. Get it checked immediately to avoid delaying repairs, or else the battery could die completely, leaving the car immobile. Safety is no small matter—take it to a repair shop to test the circuits and motor. A small investment now can buy peace of mind.

[SamuelLynn]

The key turning produces abnormal noise, and I've studied mechanical principles. It's usually an issue with the engagement between the starter motor gear and the engine flywheel, such as gear wear or misalignment, causing a scraping sound. Battery aging can also lead to insufficient current, resulting in rough motor operation. When relay contacts are burnt out, the sound may resemble chaotic clicking. Ignoring it can allow the problem to spread to the entire starting system, increasing repair costs. Early inspection is crucial—visit a shop where specialized tools can test component conditions.