Engine block
Holds the cylinders and supports the engine’s rotating parts.
Main structure of the combustion engine, below the cylinder head.
Cast passages route coolant and oil around the cylinder structure; bearing supports locate the crankshaft.
The foundation and walls of a small factory.
Coolant or oil loss, cracking or poor cylinder sealing require testing before the block is blamed.
Usually condition-based rather than a routine replacement. Lubrication, overheating and the exact engine affect wear.
Internal-engine work is usually labor-intensive. Diagnosis and the engine code determine the repair scope.
BMW engine families can use different block materials and construction; a similar outside shape does not prove interchangeability.
BMW petrol and diesel engines; petrol-only systems are identified individually.