Observation is the key to engine troubleshooting. You know your car better than anyone. This means that if it's making a sound or a smell that's not normal you will most likely notice something's awry. Many times a strange smell or sound is no big deal, but when you know that something is wrong these clues can be the key to prope3r troubleshooting.
The following areas will come up during troubleshooting analysis. Follow the trail and you will find troubleshooting salvation, or at least a shorter day of troubleshooting.