CerTech Gels Heavy Duty Truck Engine Repair Gels Engines wear down after years of use; its only a matter of time. But CerTech Gels has developed a chemical compound that reverses this wear by creating micro ceramic patches that are invisible to the naked eye. Feeling the change in engine performance and reduction in blowby is believing! As your engine runs, the gel will begin patching the wear with permanent ceramics, and you will actually feel the difference.