Learn About Being a Diesel Mechanic

What does a diesel mechanic do?

A diesel mechanic is a technician who works on diesel-powered vehicles and machines. They will spend most days inspecting vehicles, identifying problems and repairing them. Routine maintenance work is also common for a diesel mechanic. Other diesel mechanic responsibilities include:

  • Performing check-ups on diesel machinery and vehicles to check for warning signs for potential deterioration or future problems
  • Diagnosing broken diesel machinery to identify the source of malfunctions
  • Repairing damaged and non-functional units to working condition
  • Speaking with customers and asking questions to help guide inspections in order to more efficiently conduct repairs
  • Explaining problems with machinery to owners in relatable terms, then explaining work which was done and what to watch out for following repairs

Average salary

The average diesel mechanic is a full-time employee and is paid hourly. The pay level may vary depending on factors such as the individual’s experience and the type of diesel machinery being maintained.

  • Common salary in the U.S.: $23.20 per hour
  • Some salaries range from $9.30 to $43.20 per hour

Diesel mechanic requirements

Diesel mechanics typically need to have the following background: 


Many diesel mechanics earn their high school diploma or GED and then pursue hands-on education, such as an associate degree in diesel repair or service technology. Some complete specialized training programs that result in a certificate instead of a degree. Many study at a vocational school where a student receives direct training in job-ready skills with both classroom and practical lessons. 


Diesel mechanics who enter the field having completed their education at a vocational school may be able to begin working on their own immediately. If a diesel mechanic has not received a specialized education, they may be expected to work alongside an experienced mechanic at their first job for a period of weeks. This training period allows the diesel mechanic to develop their skills in a practical setting so that they can apply them on their own in the future.


Getting certified is an excellent way for a diesel mechanic to improve their career trajectory. When you have relevant certifications it can help you to secure a good job, perform better at your job, earn promotions and receive higher wages. The type of certifications to pursue will depend on the type of diesel mechanic work you are interested in. The options include:

  • Machinery: A certification from the National Center for Construction Education and Research (NCCER) is the ideal choice for a diesel mechanic with an interest in repairing and maintaining large machinery like cranes and bulldozers. The NCCER provides a wealth of resources to credentialed members, including education and aides to assist in passing the required assessments.

  • Automotive: The National Institute for Automotive Service Excellence (ASE) is a nationally respected organization offering testing certifications in a variety of focuses. Its diesel engines test consists of 65 multiple-choice questions administered in 90 minutes. The questions are designed to assess directly applicable technical knowledge. The test is a part of their Medium/Heavy Truck grouping. A mechanic interested in broader work can test in areas such as gasoline engines, suspension and steering, electrical/electronic and preventative maintenance. A mechanic earns the ASE Master Technician designation after earning six of those certifications.

  • Nautical: Mechanics with an interest in working on boats can find certification options at the American Boat and Yacht Council (ABYC). As with the ASE, the ABYC offers a variety of testing options. In addition to earning their diesel engines and support systems certification, a diesel mechanic can increase their attractiveness to employers with certifications in areas like electrical, marine corrosion, marine systems, ABYC standard and composite boat building. A diverse group of certifications will expand the diesel mechanic’s ability to find work by demonstrating a skillset to cover many potential problems on a boat, including those beyond the engine.


A diesel mechanic requires a mixture of hard and soft skills in order to excel, including:

  • Technical ability: The primary skill a diesel mechanic requires is the technical ability to complete their daily repair and maintenance tasks. The machinery being worked on is usually expensive, which makes accurate work a necessity to avoid costly errors.

  • Attention to detail: The ability to diagnose problems and identify the sources requires an observant eye to make sure no issues are missed. Strong attention to detail allows a diesel mechanic to catch even the tiniest problem in order to accurately prescribe a fix.

  • Communication: The best way to diagnose problems is often to speak with the individuals who experienced them—they can provide firsthand evidence of what went wrong. The diesel technician must be able to communicate clearly with others on staff, including those who lack in-depth technical knowledge of the diesel machinery.

  • Problem-solving: Understanding how to identify problems and then determine the solutions most likely to work is vital to a mechanic. Troubleshooting and critical thinking skills allow a mechanic to apply their technical knowledge in a practical way to diagnose and repair the machinery.

Diesel mechanic work environment

A diesel mechanic will spend the majority of their days in and around the diesel-burning machines or vehicles they are responsible for. The common work elements for this career include:

  • Standing for long periods while working on machinery
  • Getting into bent or prone positions to access hard-to-reach areas in the machinery being worked on
  • Working with mechanical tools, including pneumatic tools, to generate increased torque and power required for successful repairs
  • Speaking with drivers or clients to gather the information needed to begin troubleshooting and repairing problems

How to become a diesel mechanic

If you would like to become a diesel mechanic, here are the most common steps:

  1. Graduate high school. A high school diploma or GED will not be required for every diesel mechanic position but will be the minimum expectation for many employers.

  2. Gain specialized skills. When pursuing a career as a diesel mechanic, practical skills are often more-highly valued by prospective employers than a formal education. Training with a specific focus on working with diesel engines is a must if you want to impress a hiring manager. This can be completed during high school by attending a vocational school, after high school in an adult education program or through an apprenticeship or entry-level position, which includes working alongside more experienced mechanics and learning from them.

  3. Earn certifications. Adding one or more certifications to your resume is useful for showing your expertise in the field, particularly if you lack many years of experience. Although diesel engine focuses are the most important, additional designations in related mechanical specialties are also useful on a resume.

  4. Prepare a resume. Build a base resume that highlights your most impressive skills and prior work responsibilities that apply to a career as a diesel mechanic.

  5. Tailor your resume for the job. Create specific resumes for each job listing you’re applying for. Call special attention to your skills and work history that closely align with the posting.

Diesel mechanic job description example

Jefferson Trucking Co. is seeking a professional and reliable diesel mechanic to oversee repairs and maintenance on a fleet of two dozen trucks. The successful candidate will be responsible for speaking with drivers upon their return and discussing any troubles experienced on the road, as well as performing check-ups to identify and repair any malfunctions. The mechanic will be expected to perform standard scheduled upkeep on trucks to keep the fleet on the road and functioning at its best. ASE diesel engines certification preferred.

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