Diesel Mechanic Career Information
rom transporting goods across the country to constructing new buildings to delivering children to school, diesel engines power a wide range of vehicles that are essential to daily life. Because these vehicles take on such vital tasks, it is important that they stay in good working condition. That's why diesel mechanics are so valuable to the automotive industry. Keep reading to find out exactly what a diesel mechanic is, the types of tasks that diesel mechanics perform, what their educational requirements are, how much they get paid, and much more.
What is a Diesel Mechanic?
Basically, a diesel mechanic is an automotive mechanic who has the specialized skills to repair, maintain, and rebuild diesel engines.
Diesel engines tend to be the preferred choice for heavy types of vehicles (such as trucks, tractor trailers, buses, trains, bulldozers, ships, and many more). This is because they are capable of generating more power than standard engines. The factors that set diesel engines apart from regular gas engines include:
- Fuel—Diesel fuel has longer chains of hydrogen and carbon atoms than regular gasoline, making it heavier and more efficient when burned within an engine.
- Fuel injection—In diesel engines, air is compressed separately before fuel is injected, allowing for higher compression ratios.
- Fuel combustion—The high compression ratio makes it possible for fuel molecules to be forced into tight spaces, improving the ability to mix air and fuel, thereby creating more power from fuel combustion.
- Air intake—Unlike gas engines, which limit the amount of air entering the engine, diesel engines have no restrictions on air intake. This allows for greater amounts of both fuel and air to enter the engine in order to help it reach higher speeds.
- Spark plugs—While gas engines require spark plugs to ignite fuel, diesel engines do not because the high compression ratio heats air to very high temperatures.
- Size—Diesel engines are bigger and heavier than regular engines. This helps make them more powerful, but it also means that they are slower to warm up and accelerate. Glow plugs and engine heating systems are sometimes required to get a diesel engine to start in cold temperatures.
Because of these differences, diesel mechanics require a separate set of skills and knowledge than that of regular mechanics.
What Does a Diesel Mechanic Do? (What is a Typical Diesel Mechanic Job Description?)
A diesel mechanic job description can be quite long and extremely varied. Some of the most common procedures that diesel mechanics are responsible for include:
- Taking vehicles for test drives to help diagnose issues
- Inspecting vehicles, engines, brake systems, transmissions, and other vehicle parts (usually following a checklist of standard inspection procedures)
- Performing oil changes, battery inspections, and other routine maintenance tasks
- Diagnosing issues through inspection or usage of diagnostic equipment
- Repairing and/or replacing parts, components, electrical systems, etc.
- Disassembling, repairing, and reassembling parts and equipment
- Aligning and/or adjusting wheels
In addition, diesel engines often require complete rebuilds (usually after every 100,000 miles of usage) due to the strenuous nature of the work they perform. Another task that is becoming common is retrofitting diesel engines with emission-control systems in order to ensure that they comply with environmental or pollution regulations.
Outside of hands-on maintenance and repair, diesel mechanics usually need to perform some administrative and customer service tasks, especially if they work in smaller shops or become shop owners. Such tasks can include scheduling appointments, explaining diagnoses, providing estimates, processing payments, and more.
What are the Diesel Mechanic Requirements I Should Know About?
In the past, diesel mechanic requirements (in terms of education and credentials) were basically non-existent. Although there are still no legal requirements today (and some employers may still be willing to hire those without a formal education), more and more employers have started to prefer hiring people who hold a post-secondary education in diesel engine repair or a similar field. Some employers may also prefer or even require employees to have industry certification, which usually involves completing a diesel mechanic program at an accredited educational institution, passing an examination, and then keeping up with renewal fees and ongoing continuing education requirements.
Alternatively, you can choose to go the apprenticeship route. Apprenticeship programs are usually provided by union or government organizations, but some may be held in partnership with a post-secondary institution. The majority of these types of programs involve theoretical classroom teaching, followed by on-the-job training, working under the supervision of an experienced diesel mechanic within an actual diesel repair setting. Once you have completed an apprenticeship, you will be considered a "journeyman" (which basically means an entry-level employee who is allowed to work with minimal supervision).
However, it's important to note that some apprenticeship programs (especially ones associated with major unions) may give preference to applicants who have already completed a post-secondary education in diesel mechanics. So it's vital that you fully research the terms and prerequisites of any apprenticeship program you consider. Other requirements can include being at least 18 years of age, having a high school diploma or GED equivalent, and successfully taking an entrance exam.
In order to prepare for a post-secondary program or apprenticeship, it can help to take high school courses related to automotive repair, mathematics, and electronics.
What Can I Expect to Learn at a Diesel Mechanic School?
If you are interested in learning how to become a diesel mechanic through a post-secondary education, then here is what you can expect diesel tech training to include:
Theory and administration
- Fundamentals of diesel technology
- Interpreting technical manuals and electronic diagnostic reports
- Booking appointments for maintenance and repairs
- Customer service (answering questions, explaining diagnoses, etc.)
- Administration (providing estimates, handling billing, processing payments, etc.)
- Oil changes
- Battery inspections
- Wheel alignment
- Visual inspections of all parts, systems, and electronics
- Rebuilding engines
- Using diagnostic equipment to pinpoint necessary repairs
- Using industry-current tools and equipment (pneumatic wrenches, jacks, hoists, wrenches, screwdrivers, and many more)
- Disassembling, repairing, and reassembling equipment and parts
- Repairing (or replacing) parts, electrical systems, components, and more
- Retrofitting engines with emission-control systems
Most diesel mechanic programs also include on-site practical training, allowing you to work on diesel-powered vehicles using industry-standard tools and equipment. Alternatively, some programs may offer an off-site externship during which you work under the supervision of experienced diesel mechanics.
In addition, some programs provide the opportunity to choose a specialty. This can allow you to choose a specific type of diesel vehicle to work with, such as locomotives, buses, construction equipment, 18-wheelers, etc. Most programs offered by accredited schools also include exam preparation for common industry certifications.
If the program you choose is affiliated with a union or government apprenticeship program, then your training can include highly supervised—but paid—experience working within the industry. Apprentices typically earn 50 percent of regular wages and perform basic tasks such as checking oil levels, cleaning parts, and moving vehicles in and out of the shop area. After three to four years, you can generally achieve "journeyman" status and start taking on more advanced and unsupervised tasks related to diagnostics, repair, and maintenance.
If you take a short-term, career-oriented diploma or certificate program, then chances are that the majority of your training will be hands-on. On the other hand, if you go for an associate degree program, you will most likely also receive plenty of theoretical background instruction, as well as general education and business training.
What Does Diesel Mechanic Training Cost?
The cost of a diesel mechanic program is generally affected by a few factors, including:
- The type of educational institution offering the program
- The length of the program
- The education level of the program (certificate, diploma, degree, etc.)
Tuition can also fluctuate depending on what it covers. If your tuition simply covers the cost of training, then it may be on the lower end of the scale. However, if it also includes certification exam fees, equipment, tools, or union fees, then it can be quite a bit higher. (But remember that even if these fees aren't included in your tuition, the cost will still need to come out of your pocket separately after graduation.)
With these factors in mind, it's safe to say that you can expect to pay anywhere from a few thousand dollars up to $30,000 or more for a diesel mechanic program.
How Long is a Diesel Mechanic Program?
The length of a diesel mechanic program depends entirely on the type of program and the type of school you choose. But, on average, the short-term certificate or diploma programs offered by vocational or community colleges can be completed in anywhere from six months to a year. Associate degree programs from private colleges and universities tend to be longer, usually between two to four years.
Apprenticeship programs also tend to take multiple years to complete, but you may receive income part of the time since apprentices do tend to receive a portion of typical entry-level diesel mechanic wages (usually 50 percent).
Is Certification Required to Work as a Diesel Mechanic?
Although certification isn't legally required to work as a diesel mechanic, many employers will hire someone who has taken the time and effort to become certified over someone who hasn't. That's because most certifying associations have prerequisites that involve experience and educational credentials, as well as examinations which thoroughly test and verify your skills and knowledge.
The most common certifying association for diesel mechanics is the National Institute for Automotive Service Excellence (ASE). The ASE administers exams for over 40 different types of computer-based tests. Some of the ones that relate to diesel mechanics include:
- Medium-Heavy Truck
- Truck Equipment
- School & Transit Buses
- Auto & Truck Parts
In order to become certified, you must register with the ASE and choose the tests you wish to take. Most tests cost $30, except for advanced tests which can cost up to $60. You will also be required to pay a $36 registration fee. Once your registration is complete and you have paid the fees, you will receive a two-month timeframe (called a testing window) in which you must visit your nearest test center and complete the tests. Tests are held weekdays and weekends four times per year.
The tests typically consist of multiple-choice questions. Practice tests and study materials are available from the ASE for use during your preparation. Once you have passed all of the tests you selected during registration, you will officially be certified by the ASE. Your certification will be valid for a five-year period, after which you must re-take the corresponding tests. You will be required to pay recertification test fees, but the fees are capped off at $90, regardless of how many you take.
What is the Average Diesel Mechanic Salary?
The typical diesel mechanic salary range can vary depending on multiple factors, including:
- Level of experience—The more years you have worked in the field, the higher your salary can be.
- Position—Apprentice diesel mechanics and regular diesel mechanics tend to make less than foremen, managers, and shop owners.
- Work environment—Your work setting can affect your salary rate. For example, those who work for federal, state, or local government may earn more than those who are employed at a private repair shop.
- Location—The city or state you live in can affect your wage since salary rates fluctuate across the country.
According to national estimates from 2010, annual wages were as follows: *
- Median annual wages were $40,850.
- The lowest 10 percent earned less than $26,550.
- The highest 10 percent earned more than $60,830.
Other factors that can affect salary include hours and overtime. Most diesel mechanics put in full-time hours, and opportunities for overtime are common, especially within private repair shops that want to offer extended hours of service during evenings and weekends. Plus, many bus and truck repair shops offer their services 24 hours a day. Additionally, some employers (most commonly truck fleet dealerships and repair shops) offer diesel mechanics a base salary with a commission paid on top of it, making it possible to earn a higher-than-average annual salary.
Where Do Diesel Mechanics Work?
Diesel mechanics can find employment in a variety of settings. Some of the most common work environments include:
- Automotive repair and maintenance shops
- Wholesale vehicle and parts companies
- Vehicle and equipment dealerships
- General or specialized freight truck companies
- Manufacturing or construction companies
- Bus and public transit companies
What is the Job Outlook for Diesel Mechanics?
According to government projections from 2010, diesel mechanic employment is expected to grow 15 percent by 2020.* This is about on par with the overall average growth rate for all occupations. The reasons behind the projected growth include:
- Increased need for freight to be shipped cross-country, meaning more diesel-powered vehicles being used and requiring maintenance and repairs
- Current vehicles within truck fleets requiring increased maintenance as they age
- Older vehicles needing to be retrofitted or modernized in order to comply with new environmental regulations
What are Useful Qualities for a Diesel Mechanic to Have?
Aside from any knowledge or skills gained within a classroom, there are some natural abilities or strengths that are coveted within the field of diesel mechanics. They include:
- Manual dexterity—You will be required to work on small parts within small spaces. In order to do the job well, you must have steady hands and excellent hand-eye coordination.
- Mechanical aptitude—Some people are just naturally mechanically inclined. They seem to intuitively understand how and why things work without having to be told. Obviously, this can be a huge asset to a diesel mechanic.
- Technical aptitude—Just like with mechanical aptitude, some people have a natural ability to understand technology. Since today's diesel engines involve electronic systems, it can be a huge help for a diesel mechanic to be technically inclined.
- Problem-solving abilities—The source of mechanical issues isn't always obvious at first glance. Sometimes the reason for automotive issues can be downright mysterious. Therefore, problem-solving and troubleshooting abilities are essential.
- People skills—You might think that people skills aren't required for a hands-on, skilled-trades career like diesel mechanics. However, you will be required to talk and interact with a variety of people each day, from fellow mechanics to shop owners or managers to customers. It is especially important for diesel mechanics to be able to listen to customer needs and remain helpful and courteous at all times.
What are the Pros and Cons of Becoming a Diesel Mechanic?
It's to be expected that every job comes with both positive and negative aspects. Diesel mechanics who are truly passionate about the automotive field usually love what they do and find that the satisfaction outweighs any aggravations. Regardless, it is important to have a solid understanding of the good and the bad before entering this career field. Here are some of the most common pros and cons of a career as a diesel mechanic:
- The need to "pay your dues"—You will likely have to start at the bottom of the food chain in terms of salary and job duties, especially if you choose the apprenticeship route. It will take hard work to earn a solid paycheck and gain the required trust to take on more advanced duties.
- Expenses—You may have considerable start-up costs since many diesel mechanics find that they need to buy their own tools. This is especially true of those who want to start up their own maintenance and repair businesses.
- Stress—If you work within a repair shop, you may be faced with considerable pressure due to tight deadlines for vehicle repairs.
- Cranky customers—Vehicle repair can be a touchy subject for some people. Many people rely on vehicles as part of their livelihood, and they can become emotional about them, especially when maintenance or repairs end up costing more than the original estimate. Mechanics often must bear the brunt of an owner's frustration.
- Injury—Minor injuries are common in the automotive repair field due to the required heavy lifting and the necessity of spending long periods of time in uncomfortable positions. Occasional cuts, burns, and bruises also tend to be unavoidable.
- Personal satisfaction—It can be incredibly satisfying to know that you are helping people protect their livelihoods by ensuring their safety out on the road or on construction sites.
- The thrill of cool technology—Since automotive technology is continually evolving, you will have the chance to experience ongoing learning and work with exciting new technologies on a regular basis.
- Transferrable skills—You can utilize your skills and knowledge outside of your job. Not only can you handle your own vehicle repairs, you could even make a profit on the side by buying, fixing, and re-selling older or broken-down vehicles.
- Physical activity—You can enjoy an active, hands-on career that helps you to keep in shape and allows you to avoid spending hours sitting behind a desk.
- Fun interactions—You can meet and interact with a variety of people each day.
What Should I Do Next?
If you are still interested in pursuing a future in diesel mechanics now that you have a better understanding of the who, what, where, and why of this field, then begin by checking out this guide to diesel mechanic schools and programs. Search through the available options and request more information about the ones that spark your interest today!
* Bureau of Labor Statistics, U.S. Department of Labor, Occupational Outlook Handbook, 2012-13 Edition, website last visited on September 26, 2012.
The National Institute for Automotive Service Excellence (ASE), website last visited October 31, 2012.
The Automotive Service Association (ASA), website last visited September 21, 2012.
The Association of Diesel Specialists (ADS), website last visited September 21, 2012.
The Diesel Technician Society (DTS), website last visited September 26, 2012.