The average cost to rebuild an engine is typically $300 to $1,200. An older air-cooled engine is on the low end of the scale, while small block eight-cylinder engines are higher in price. An engine needing block and head machine work adds to the price.
When an engine is rebuilt, the lower half of the engine is removed first and sent to an automotive machine shop to be disassembled, assessed and cleaned. The internal parts of the engine are then assessed and replaced if necessary. The most common sign an engine needs to be rebuilt is high oil consumption and excessive white smoke in the exhaust.