How Can I Become a Diesel Mechanic? If you wish to enroll into an accredited online diesel technology program, take a moment to review potential diesel mechanic schools near you. In some cases, community colleges or vocational schools may allow a student to simultaneously enter a diesel-engineering program while obtaining an equivalency degree. You must also be at least 18. A certified master diesel mechanic will make more money than someone in the same position who has just graduated from high school. Diesel mechanics work on engine operations and computerized management systems for trucks and other diesel vehicles. A person can become a diesel mechanic through formal training or on-the-job training with large companies. Featured Program: Penn Foster Career School's online Diesel Mechanics & Heavy Truck Maintenance career diploma program covers basic diesel engine operations, troubleshooting and repair and more. On the other end of the scale, a diesel mechanic working in the gas and oil industry could make up to $68,480 per year. To become a diesel mechanic, you need to pass your high school diploma (HSD) or equivalent GED (General Educational Development) certificate. Finally, due to legal reasons, most employers require that anyone seeking to become a diesel mechanic be at least 18 years of age, and also have either a high school diploma or a GED degree. Salary is also determined by years of experience and certification level. The program helps you to prepare for the National Institute for Automotive Service Excellence (ASE) Certification Medium-Heavy Truck Tests. Diesel mechanic; Diesel parts and service manager; Earning an online degree in diesel technology can open many new doors in the mechanical industry, allowing you to find a position at an upstanding company. There are different levels of diploma, certificate, and degree programs available for people pursuing this career. There are a lot of opportunities for diesel mechanics, including automobile, truck, and bus servicing, industrial or government fleet servicing, manufacturers, and repair shops or service stations, or even starting your own business. Requirements to Become a Diesel Mechanic Online.