How to Find a Crack in a Cylinder Head

A small engine cylinder crack is hard to find.

Modern engine cylinders are built with lightweight materials that crack easily under pressure. Cracked cylinders create a lot of problems for an engine, loss of power being one of them. Head failure is usually caused by a cracked head. Cracks tend to form when there is a great deal of heat stress in the engine. The heat causes the metal to expand, making the crack appear. It is important to find the crack immediately to prevent head failure.

Instructions

1. Inspect underneath the car and near the cylinder for leaking coolant.

2. Remove your cylinder head, and degrease the component by spraying it with a degreaser and rubbing it with a wire brush. Rinse the part and dry it off. Inspect the head for carbon build up or rust. Remove rust and carbon with a wire brush.

3. Look for cracks on the cylinder head using a magnifying glass. Inspect around the number three spark plug area.

4. Put on gloves and a mask, and spray a dye/penetrant substance onto the cylinder in a well-ventilated area. Allow the dye to dry. Spray the part with the developer that comes with the product. This will create a pink color where there are cracks in the cylinder.

References

• Engine Builder Mag: Finding Cracks
• Custom Pistols: Crack Inspection for the Hobbyist