How Are Mechanical Problems Diagnosed?

Aside from using car diagnostic tools, mechanics diagnose mechanical problems using their experience. This allows them to come up with a diagnosis without needing to do much inspection.

As cars and their parts become more modern and computerized, detection of problems typically requires the use of electronic devices or mini computers. When smell, sight, sound, or a test drive cannot detect the problem, mechanics rely heavily on car diagnostic tools.

Car Diagnostic Tools and Their Uses

Not all mechanical problems need to be diagnosed with high-tech devices. An experience mechanic can properly detect some problems with a low-tech tool or two at most. To diagnose mechanical problems, mechanics use some basic tools including:

  • 12v test light – to detect electrical problems
  • Stethoscope (mechanic) – to pinpoint the location and cause of car noises
  • Timing light – helps to check engine timing
  • Vacuum gauge – to check engine performance and pinpointing issues.
  • Fuel pressure gauge – to detect the level of fuel pressure being exerted to the engine.

Scan Tools Used to Diagnose Mechanical Problems

Code readers and scan tools are high-tech car diagnostic tools that mechanics use mainly for newer cars that have computers. These tools basically generate codes from the car's computer to signify mechanical problems that may be going on. Mechanics then research these codes to determine what they need to do for repairs.

Scan tools, on the other hand, are code readers with a few more features. Scan tools, like code readers, allow mechanics to read and clear codes from a car's computer. However, a scan reader also allows you to view all available data for your car's computer. Scan readers also provide a bit more insight on the mechanical problems your car is facing. Instead of just generating codes, they also provide a brief description of what the code means.

Scopes and Meters

Another vital tool for diagnosing mechanical problems is a multimeter. This auto diagnostic tool can test a range of issues in your car. You can diagnose everything from the electrical system to the O2 sensor. More complex scopes and meters often combine both the scope and troubleshooting procedures all in one. In effect, it makes diagnosing and creating a plan for repairs a lot more efficient.


Experience is another tool at the mechanic’s disposal to aid in diagnosing mechanical problems. Through education and experience from past automotive repairs, mechanics can often diagnose a problem without having to hook it up to any machine. Using sight, smell, and touch as guides, a mechanic can tell when certain things are wrong.

Diagnosing mechanical problems will greatly depend on the age of your vehicle. For cars that are more than 15 years old, mechanics use experience and basic tools to diagnose mechanical problems best. However, for newer cars equipped with a computer, mechanics use diagnostic tools such as those above to pinpoint problems. You can buy many of these tools (apart from experience) online and use them without a mechanic's help.

Got mechanical problems that are just too much to be bothered with? CarScrappers buys cars with mechanical problems and will give you the best rate possible. Give us a call at (855) 929-0828 for more information.

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