* Solenoid Engagement: The starter solenoid is the electromagnetic switch that engages the starter motor's gear with the engine's flywheel. Even a new starter can have a faulty solenoid. The clunk could be the solenoid trying to engage but failing to fully connect.
* Flywheel Teeth: The teeth on the flywheel (the part the starter engages) could be damaged, worn, or broken. This would prevent the starter from properly meshing and turning the engine.
* Starter Gear: Though you have a new starter, the bendix gear (the part that extends from the starter to engage the flywheel) could be malfunctioning, bent or not retracting properly. This is less likely with a new starter but possible.
* Neutral Safety Switch: This switch prevents the vehicle from starting unless it's in Park (automatic) or Neutral (manual). If this switch is faulty or its wiring is damaged, it won't allow the starter circuit to complete. Check that the transmission is definitely in Park or Neutral.
* Ignition Switch: The ignition switch itself could be failing, preventing power from reaching the starter solenoid.
* Wiring Issues: Loose, corroded, or damaged wiring anywhere in the starter circuit (between the battery, ignition switch, solenoid, and starter) could also cause this problem. This is especially critical considering the age of the vehicle.
Troubleshooting Steps:
1. Check the Neutral Safety Switch: Make absolutely sure the transmission is in Park (automatic) or Neutral (manual). Try jiggling the shifter slightly.
2. Listen Carefully to the Clunk: Try turning the key while someone listens closely to where the clunk is coming from. Is it definitely from the starter area, or somewhere else under the hood? A precise location helps narrow down the issue.
3. Check the Battery Connections: Even with a new battery, loose or corroded terminals can cause starting problems. Clean and tighten all battery and ground connections.
4. Inspect the Starter Solenoid: If you're comfortable working on cars, you can try tapping the starter solenoid gently with a hammer while someone turns the key. This is a risky test and shouldn't be done if you're not familiar with car repair. A successful start this way confirms the solenoid is at least a suspect.
5. Have it Professionally Checked: If you're not comfortable troubleshooting the issue yourself, take it to a mechanic. They have the tools and expertise to diagnose the problem accurately and efficiently. They can test the starter solenoid, check the flywheel teeth, and assess the wiring.
Given the consistent clunk and the parts you've already replaced, it's likely a problem with the engine's engagement mechanism, or possibly a more significant electrical problem requiring professional attention. Don't continue to crank the engine repeatedly, as this can damage the battery further.
