- Many times, a vehicle with a cracked engine head, which is the top part or top end of a vehicle's engine block, will leak motor oil out of the cracked part of the head. An engine head houses the valve train, which is bathed in motor oil throughout engine operation. A cracked engine head, specifically one with a large crack, can leak oil.
Low Engine Compression
- A cracked engine head allows engine combustion pressure to escape, thereby lowering engine compression and negatively affecting engine performance. A compression test performed on an engine with a cracked head will often show dramatically reduced engine compression.
- Just as motor oil can leak out of a cracked engine head, engine coolant can leak out as well. Circulating engine coolant, which travels through an engine head, can leak out of a severely cracked head and lead to an engine overheating by diminishing the coolant level of an engine.
Engine Head Smoke
- As a vehicle's engine operates, engine combustion gases are constantly being ignited and burned, a process which produces exhaust gases and bits of smoke. If a cracked engine head is big enough or in the right position on top of the head, engine combustion gases and smoke can filter up into the engine head and leak out.
- Many times, a vehicle with a cracked engine head will miss or run erratically. This is due to the escaping combustion gases that can seep out of a cracked engine head, an occurrence that greatly diminishes engine power and interferes with proper combustion of an engine's air/fuel mixture.