Obvious Signs:
* Complete inability to start: This is the most obvious sign. You'll turn the key, and the engine won't even crank. It might make a clicking sound (starter motor issue, but still indicates a problem that *could* be related to a seized engine), but there will be no engine rotation whatsoever.
* Resistance when attempting to rotate the engine by hand: If you can access the crankshaft pulley (usually at the front of the engine), try turning it by hand with a wrench. If it's seized, it will be completely impossible to turn. Even significant resistance is a major red flag.
Less Obvious but Still Strong Indicators (Often Precursors to a Complete Seizure):
* Overheating: Severe overheating, often accompanied by steam, is a common precursor to a seizure. Lack of lubrication leads to friction and heat build-up, ultimately causing parts to bind.
* Knocking or unusual noises: A seized engine might make a loud knocking or grinding sound *before* it completely seizes. These sounds often indicate that parts are already damaged and nearing failure.
* Loss of oil pressure: The oil pressure gauge reading zero or extremely low is a critical warning sign. Without sufficient lubrication, the engine components will quickly overheat and seize.
* Loss of power: Before the engine fully seizes, you might experience a gradual loss of power and performance. The engine might struggle to accelerate or maintain speed.
* Smoke from the engine compartment: While smoke can indicate many issues, white or bluish smoke *especially after overheating* might suggest severe internal damage.
Important Considerations:
* Don't force it: If you suspect a seized engine, do *not* attempt to start it repeatedly. This will cause further damage and potentially lead to more expensive repairs.
* Professional Diagnosis: While the signs above are indicative, it's crucial to get a professional mechanic to diagnose the problem conclusively. They have the tools and expertise to determine the extent of the damage and the best course of action.
If you're experiencing any of these symptoms, particularly the inability to crank the engine or significant resistance when attempting to rotate the crankshaft, it's highly likely you have a seized engine and require professional assistance.
