
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.

I've been driving a Nissan Sunny for seven or eight years and have encountered the issue of the engine getting louder several times. The most common reasons are insufficient engine oil or oil that's too old, leading to inadequate lubrication and increased friction noise between parts. It could also be due to a loose belt or a worn tensioner, causing a rattling sound during operation. Additionally, if the muffler in the exhaust system is damaged, exhaust gases are expelled directly, significantly increasing noise. Too much carbon buildup on the spark plugs can cause poor ignition, leading to engine shaking and louder sounds. Regularly changing the oil and checking the belts and exhaust system can prevent many of these issues. If the noise persists, it's best to get it fixed promptly to avoid higher repair costs later, as well as impacts on fuel efficiency and safety. Over the years, I've learned that addressing small issues promptly can save a lot of money.

I bought this Nissan Sunny second-hand and drove it for over a year when suddenly the engine became extremely loud. After some research, it might be because I delayed maintenance and didn't change the engine oil on time, causing it to become dirty and lose its lubrication effect. Or perhaps the exhaust modification resulted in poor noise reduction, although I didn't alter the original setup. It could also be due to increased carbon buildup from highway driving, causing unstable idling and loud noises. The loud engine noise is particularly annoying, making driving feel like operating a tractor and ruining the driving experience. I suggest first checking the oil dipstick to see the oil level—if it's dirty, change the oil immediately. If the issue persists, quickly take it to a repair shop to inspect the exhaust pipe and belts to avoid causing engine damage.

As a family user, the loud engine noise of the Nissan Sunny is really unsettling. The noise is not only harsh but may also indicate potential safety hazards, such as oil leaks or a belt about to break, which can easily lead to breakdowns during long-distance trips. It's even more concerning if you have children, as the risk of the car suddenly breaking down on the road is high. I usually pay attention to maintenance intervals, as insufficient lubrication or aging parts are common causes in older cars. While driving, I stay alert to any changes in sound and pull over to check if there are noticeable abnormal noises, avoiding forcing the car to continue. For the safety of the whole family, I regularly take the car to the 4S shop for comprehensive inspections—prevention first saves money and peace of mind.


