This can happen if there is a broken tooth on the starter. It can be a broken tooth on the fly wheel but more than likely it is the starter tooth that is broken. Or the starter sylenoid is bad in the starter.
The starter is stuck or apparently engaged, replace the starter to eliminate your problem.
Either the ign. switch is faulty, or the starter is faulty Or the starter solenoid is stuck closed, so the starter is constantly engaged and getting voltage from starter relay. If so you would need to replace the solenoid.
The starter solenoid is sticking or stuck.
If the starter is whining while the engine is running at an idle you have a problem with the ignition switch or the starter solenoid is stuck. The starter should not be engaged while the engine is running unless you are holding the key over on the start position.
A new starter remains engaged while the engine is running primarily due to a malfunction in the starter relay or solenoid. When the engine starts, the ignition system should cut power to the starter, but if there's a wiring issue or a stuck solenoid, the starter gear may remain in contact with the flywheel. This can lead to excessive wear and potential damage to both the starter and the engine components. Proper diagnosis and repair are necessary to prevent further issues.
In a Chevy Cavalier, if the starter turns over without the key switch being in the "on" position, it may be due to a malfunctioning ignition switch, a short circuit in the wiring, or a stuck relay. Additionally, a faulty starter solenoid could also cause the starter to engage unexpectedly. It's important to inspect the electrical components to diagnose the issue accurately.
Could be the bendix in the starter is stuck. all you have to do is tap the starter to get it to release. then try starting it again. If that doesn't work then the starter is probably finished.
The 1991 Ford Explorer should have a separate starter relay that sends power to the starter. It sounds like the relay has stuck and is sending power to the starter even after the vehicle is running.
just work with it until you get it open. try getting in and kicking from the inside...
how to remove key stuck in ignition switch in Chevy colbalt
Solenoid the starter is stuck would be my suspicion.
Are the battery leads making a tight contact? - checkIs the starter motor stuck? - give it a gentle tap with a hammer.