An engine core is a used engine sold as a starting point for a rebuild, or returned as part of a core exchange. It is not sold as a running engine.

Why cores have value

The most valuable parts of an engine, such as the block, crankshaft and cylinder heads, can often be machined and reused. Engine rebuilders and machine shops buy cores for those parts. For rare and classic engines, a core may be the only way to get an original block.

What condition to expect

Usually not running, and sold as-is
Often missing components such as accessories, sensors, manifolds or the oil pan
May have internal or external damage
Needs inspection, machining and rebuilding before use

Core charges and core exchange

When you buy a rebuilt or remanufactured engine, some suppliers add a core charge that is refunded when you return your old engine. Ask whether a core charge applies, what condition the returned core must be in, and how long you have to return it.

Buying a core

Confirm the engine code, casting numbers and the list of missing parts, and ask about known damage such as cracks or a seized engine. Photos of the block and any stamped numbers help.

Looking for a core? See engine cores or request sourcing.