How to Troubleshoot Your Car

For the DIY mechanic, there is perhaps no more important step in fixing a vehicle than the troubleshooting process. You want to find out what is wrong with your car in an expedient manner without wasting a lot of time and energy. Typically, the DIY mechanic also does not want to spend unnecessary money either. The keys to troubleshooting a car are paying attention to the symptoms and the process of elimination.

Symptom Checker

The very first step to troubleshooting a vehicle is to pay attention to the symptoms it is exhibiting. How does it feel, smell, look and sound? To aid you in this process of checking symptoms, there are various tools online, such as on AutoZone, that have symptom checkers similar to a medical site like WebMD. These can be very helpful in narrowing down issues. For example, suppose your car is stumbling upon acceleration. That is a feel issue, as you can feel it stumble when you depress the gas pedal. You know it's related to something in the engine compartment. Upon checking this symptom, you will find a range of parts that might be at fault.

Begin with the Easiest, Cheapest Fix

The next step is to determine which part is the easiest and cheapest to fix. For example, in the previous problem, you have figured out that a range of parts related to spark could be at fault. This usually includes spark plugs, wires, the distributor, the distributor cap, and the rotor. Of these, the plugs and distributor are the most expensive fixes. The least expensive are usually the rotor, wires and sometimes the cap. Some vehicles require a cap that includes wires, and that part is more expensive.

Process of Elimination

Now that you've made a list of possible culprits and know which ones are the easiest and cheapest to fix, it's time to begin the process of elimination. Check the cheapest parts first and replace them if necessary. After each replacement, drive the vehicle and wait for the problem to reveal itself again. If the problem persists, then move to the next cheapest and easiest part. Continue until you have found and corrected the problem.

In the aforementioned real-life example of a 1993 Toyota Celica, the mechanic replaced the cap and rotor first as those were the cheapest. The rotor showed signs of wear and the cap was cracked. However, neither of these replacements fixed the problem. The next step was the spark plug wires, which were relatively inexpensive in this car's case. The spark plugs were checked as a precaution but did not show signs of needing replacement. It turned out instead that the wires were indeed the culprit and the acceleration problem disappeared. Case closed.