Machine shops undertake general mechanical work that includes fabricating new parts or repairing old ones. The automotive machine shops undertake the repair of cars or vehicles, which may include motorcycles also. Some automotive machine shops are brand-specific. This means that they repair vehicles of one particular brand, which may be Ford, Nissan, Toyota, and so forth. These are usually company-authorized automotive repair shops. The repair work may include engine cleaning and dust removal, the checking of cranks, rods, blocks and heads, as well as suspension parts of race cars, crack repair of blocks and heads, crank shaft grinding, polishing and hardening, block boring, complete engine balancing, and connecting-rod stress relieving.

There are automotive machine shops that take up all types of vehicular repair work irrespective of brand. They also undertake the repair of older vehicles, the so-called 'yesterday' machines, whose parts and accessories are not easily available. It goes without saying that the engineers and mechanics in these shops are highly skilled, as they sometimes have to improvise or almost reinvent the rare spare parts. The job of these generalists is also more labor-intensive and time-consuming. It naturally follows that their charges are usually higher than ordinary work of similar nature.

Both brand-specific and general repair shops also supply or fabricate new parts to replace the damaged ones if they are beyond repair.

A point of concern is that these machine shops use hazardous materials for their repair work and release environmentally harmful waste materials. For example, they use methylene chloride to clean the aluminum parts. This solvent is toxic in nature. If it is not properly disposed of it may prove dangerous to the environment. So, apart from repairing and fabricating machine parts, the machine shop owners also need to be responsible for protecting public health and the environment. If they release the pollutants down the sewer, they are likely to be punished heavily with fines and other penalties.