[Bob Bidonde]

After many attempts to loosen cylinder heads by running the engine with the head nuts off, it has not once worked. This is especially true when the head gasket is already leaking.

Penetrating oil and driving metal wedges into the gasket works, but it is a difficult and slow process. Be careful not to pry upward on the wedges because it is easy to damage the surfaces of the block and head. Let the geometry of the wedges do the uplifting.