Tools for Diagnosing Car Problems

• The multimeter is found in most mechanics' tool boxes. The Readout image by Cinneman from Fotolia.com

  The automobile has evolved from a simplistic machine requiring a few hand tools to maintain into a complex, computer-controlled vehicle. The modern car requires a wide array of tools for a mechanic to perform an accurate diagnosis. The toolbox of a mechanic working on newer vehicles will range from simple hand tools to data loggers specific to a single make and model. Modern mechanics often undergo extensive training before working on different models.

On-Board Diagnostics Tools

• Computer-equipped vehicles are difficult to diagnosis due to their complexity. Luckily, the engineers designing these vehicles devised methods for the cars to perform a level of self-analysis and communicate that to the mechanic. On-Board Diagnostics was available in some vehicles starting in 1985. In 1996, the second version of OBD was produced in most mass-manufactured vehicles.

  To view the data provided by OBD, a code reader, often called a code scanner, is required. The basic code readers will allow the diagnostic codes to be viewed and erased. More sophisticated models of the code scanner will allow the mechanic to view data from sensors on the car in real time. A code reader is essential for a mechanic attempting to pinpoint the reason for a "check engine" light.

Electrical Problems

• Electrical problems are often very difficult to diagnose and resolve. The multimeter is one of the most common tools used for electrical issues. The multimeter will provide data about voltage, amperes, resistance and continuity. A simple test tool for determining if a wire is broken is a continuity tester. A direct current (DC) test probe is used to determine if a circuit has voltage by lighting a bulb in the probe.

Engine Problems

• A compression tester is used by mechanics to determine how well each cylinder is functioning by enumerating the pressure in that cylinder while the engine is cranked. To verify that the correct amount of gas is provided to the engine from the gas tank, a fuel pressure gauge is used. A timing light is a hand-held device that emits a strobe of light each time the engine rotates. This flash of light illuminates the timing mark to provide the mechanic a reference point to determine if the car is timed correctly. To measure if the vehicle is lubricating the engine correctly, an oil pressure gauge is connected to the engine.

Information Sources

• Car repair manuals are valuable sources of information for determining what is wrong with a vehicle. After-market manuals are often produced that cover several model years of one or more makes by a car manufacturer. Factory manuals are produced by the car manufacturer for use by dealership mechanics and others requiring in-depth knowledge for a specific car. These manuals are often available on compact disc, allowing them to be viewed on a computer. Factory manuals often come in several varieties such as electrical, workshop or engine manuals.