What is the consequence of a malfunctioning ignition system?

A malfunctioning ignition system can lead to a failure of the engine to start because the ignition system is responsible for creating the spark that ignites the fuel-air mixture in the engine's cylinders. If the ignition system is defective, it may not deliver the necessary spark at the correct time, preventing combustion from occurring. This lack of combustion results in the engine being unable to start or run properly.

The other options, while they may describe issues related to engine operation, do not directly correlate with the specific function of the ignition system. Overheating is typically associated with cooling system failures, fuel contamination is related to fuel system problems, and excessive noise could be a symptom of various mechanical issues but does not specifically stem from ignition system malfunction.