Why is the Nissan Sunny's engine so noisy?

[ZoeyFitz]

Nissan Sunny engine noise reasons are as follows: Valve noise: Especially when starting a cold engine, the valves will make a "ticking" sound, which improves after the engine warms up. This happens because the oil settles in the oil pan and isn't immediately "pumped" up when the engine starts. But if the valve noise persists, consider switching to a thicker viscosity oil. Engine "backfire" issue: The engine may produce a "popping" sound, often caused by excessive carbon buildup on valves or incorrect timing adjustment. Clean the valve carbon deposits and adjust the valve timing. Engine misfire: One cylinder not firing, mostly due to spark plug or ignition module failure. Replacement is needed.