If you haven't popped the hood of your car in awhile, chances are that the engine block is caked with dirt and grime. This residue, along with moisture and dry air, can make aluminum and other metals on the block susceptible to oxidation (rust) and pitting. Most minor cases of oxidation can be cleaned away without removing the engine block from the vehicle. However, if the problem is extensive, you may need to have the block removed by a professional auto body shop.
Clean caked-on grease, dirt and other residue from the block using a bristled scrub brush and a mixture of dish soap and warm water. In some cases, this may be all that is required to remove oxidation.
Smooth away minor pitting from the aluminum parts of the block using a piece of coarse grit sandpaper. Use a circular motion and apply firm pressure for best results. Wipe away aluminum dust with a damp cloth once you finish.
Saturate a pad of synthetic steel wool with oil-based lubricant. Scrub away any remaining oxidation with the pad. Reach into small nooks and crannies of the engine block using a steel brush. Wipe away remaining oil residue with a damp cloth.
Apply a generous amount of metal polish to a buffing cloth. Rub the aluminum parts of the engine block vigorously with the cloth until the desired amount of polish is achieved.
Replace the engine block if removal was necessary. If you are not comfortable performing this task or are inexperienced with automotive repair, consult a professional auto body service.
