1. Engine Knock: Using fuel with a lower octane rating than recommended for your vehicle's engine can lead to a condition called engine knocking or detonation. This occurs when the fuel ignites prematurely, causing a knocking or pinging sound. However, the presence of engine knocking is more apparent under specific circumstances, such as acceleration, incline driving, or towing, rather than being a persistent noise.
2. Check Engine Light: Incorrect octane gasoline by itself does not usually trigger the check engine light. The check engine light is typically activated when there's an issue with the engine, transmission, emissions system, or other vital vehicle components. It requires specific diagnostic trouble codes (DTCs) to be set, which are generated by various sensors and systems within the vehicle. Using the wrong octane fuel may not create conditions that directly trip the check engine light.
3. Other Causes: A tapping noise in the engine and check engine light can be indicators of other underlying problems that may not be directly related to the fuel octane rating. These could include issues such as worn engine components (e.g., valve lifters, piston rings, or rod bearings), insufficient lubrication, cooling system malfunctions, or other mechanical issues. In these cases, it's crucial to have the vehicle inspected by a qualified mechanic to diagnose and address the underlying cause.
Therefore, while the wrong octane fuel can affect engine performance and potentially lead to knocking under certain circumstances, it's not the only cause of such noises or the check engine light. Additional investigation is necessary to identify the root of the problem.
