* Hydrolock the engine: Water is incompressible. If enough gets into the cylinders, it can prevent the pistons from moving, causing severe bending or breakage of connecting rods and crankshaft. This is a catastrophic failure.
* Rust and corrosion: Water accelerates rust and corrosion throughout the engine, affecting internal components like cylinder walls, pistons, bearings, and the crankshaft. This damage might not be immediately apparent but will progressively worsen engine performance and lifespan.
* Damage to the catalytic converter: Water entering the combustion chamber can be expelled through the exhaust, and if it's significant, it can damage the catalytic converter. The sudden temperature changes can cause cracking.
* Contaminate the oil: Water mixing with the engine oil ruins its lubricating properties, leading to premature wear and tear on moving parts. This can lead to bearing failure and other significant engine issues.
* Short circuit electrical components: Water is conductive. If it reaches electrical components, it can cause shorts, potentially damaging the engine control module (ECM) or other sensitive parts.
Simply because the heads appear visually fine doesn't mean the engine is unharmed. A thorough inspection, likely requiring disassembly of parts of the engine, is needed to assess the extent of the damage. Ignoring water ingestion can lead to much more expensive repairs down the line.
