Why it's a good sign:
* No major mechanical seizure: If the engine is completely seized (like a piston stuck or a rod bent), it'll be incredibly difficult or impossible to turn by hand.
* Potential for repair: If it turns, there's a chance the issue is less severe and can be addressed with repairs.
Why it's not a guarantee:
* Compression issues: The engine may turn freely but have very low compression, indicating worn or damaged rings, valves, or cylinder head issues. This could prevent the engine from running properly.
* Other internal damage: While turning by hand, you're not putting much force on the engine. Other problems like bent rods or damaged bearings could be present and only become apparent when the engine is running.
* False sense of security: Just because it turns doesn't mean it's ready to run. It might have other problems that require further inspection and repair.
What to do next:
1. Check for resistance: Does the engine turn smoothly or with noticeable resistance?
2. Listen for unusual noises: Any grinding, clicking, or rattling noises indicate potential internal issues.
3. Investigate further: A proper diagnostic check by a mechanic is essential to determine the real cause of the problem and ensure the engine is safe to run.
Remember: Turning the engine by hand is a preliminary assessment. Don't assume it's good to go based on that alone. Have a mechanic inspect it thoroughly before attempting to start it.
