What is the consequence of operating an engine without oil?

Operating an engine without oil leads to severe damage primarily because oil plays a critical role in lubricating engine components, reducing friction, and dissipating heat. When there is insufficient lubrication due to a lack of oil, the moving parts of the engine experience excessive friction. This friction can generate extreme heat, which not only leads to overheating but also causes the engine parts to wear down rapidly.

The term "seizing up" refers to the condition where moving parts of the engine bind together due to overheating and the absence of necessary lubrication. When components seize, they can no longer move freely, leading to catastrophic engine failure. This condition often requires extensive repairs or complete replacement of the engine, making it important to always ensure adequate oil levels for optimal engine operation.