* Starter Motor Issues: This is the most common cause. The starter motor might be:
* Faulty Bendix Gear: The bendix gear is responsible for engaging the flywheel. If it's broken, stripped, or not engaging properly, the engine won't crank even though the starter motor turns. You'll hear the starter motor spinning but no engine turning.
* Weak or Failing Starter Motor: The motor itself might be worn out and unable to generate enough torque to turn the engine over. This often manifests as a slower-than-normal cranking sound before it fails entirely.
* Bad Starter Solenoid: The solenoid is the electrical switch that activates the starter motor. A bad solenoid won't allow the starter motor to engage. You might hear a click (from the solenoid) but no cranking.
* Loose or Corroded Starter Motor Connections: Check the battery cables, the ground cable to the engine block, and the wiring to the starter motor for loose connections or corrosion. Clean any corrosion you find.
* Engine Issues (Less Likely, but Possible):
* Seized Engine: While less likely if it's been running recently, a seized engine (due to low oil, a broken connecting rod, etc.) will prevent the starter from turning the engine. You'll hear the starter motor trying to spin but the engine won't budge. This is usually accompanied by other symptoms, like odd noises from the engine previously.
* Extremely Low Battery: Though you say it turns over, a *very* weak battery might have enough power to turn the starter motor but not enough to actually crank the engine.
* Neutral Safety Switch: This switch prevents the starter from engaging unless the transmission is in neutral or park. A faulty switch could prevent the starter from engaging, even if the transmission is in neutral. Check this switch particularly if it only fails to start in some gears and not others.
Troubleshooting Steps:
1. Check the Battery: Make sure the battery terminals are clean and tight. Test the battery voltage. It should be around 12.6V when fully charged. A low voltage can cause this problem.
2. Listen Carefully: Pay close attention to the sounds when you turn the key. A clicking sound often indicates a problem with the solenoid. A grinding sound suggests a problem with the bendix gear. A slow, weak cranking sound points towards a failing starter motor or a low battery.
3. Check the Cables and Connections: Inspect all battery cables, ground connections, and wiring to the starter motor for corrosion or looseness.
4. Try tapping the Starter Motor (Gently!): With the key turned to the "start" position, gently tap the starter motor with a hammer or wrench. This can sometimes free a sticking bendix gear, but *only* attempt this if you understand the risk of injury from moving parts. This is not a fix, just a diagnostic clue.
5. Check the Neutral Safety Switch: Make sure the transmission is in neutral and verify the switch is working correctly.
If you're not comfortable working on your vehicle's electrical system, it's best to take it to a qualified mechanic for diagnosis and repair. Attempting to fix starter motor issues without the proper knowledge and tools can be dangerous.
