What to do if the car engine is knocking?
4 Answers
When the knocking is slight, the engine power is slightly unstable, the engine shakes severely, and it will cause the engine to overheat and emit black smoke. The solutions for car engine knocking are as follows: 1. After the engine starts, if there is a knocking sound during low-temperature operation, and the sound disappears when the temperature returns to normal, it can be left untreated temporarily and continue to run. 2. When the engine temperature is normal, if there is an obvious knocking sound, high-speed operation should be avoided as much as possible, and the engine should be disassembled and repaired as soon as possible. 3. If the cylinder is severely out-of-round, scratched, or the gap between the piston and the cylinder is too large, it should be replaced. 4. If the connecting rod is found to be deformed, it should be replaced as much as possible.
Last time my car's engine also had a knocking sound, like metal constantly hitting, especially loud when accelerating uphill. The cause might be using low-octane gasoline or ignition timing too early, leading to mixture detonation; sometimes it's due to excessive carbon buildup or loose pistons. I checked the oil level myself, listened for the source of the noise, and tried switching to higher-grade fuel. If the sound stops, it's fine, but if it persists, it could be a connecting rod or bearing failure, and you should stop the car immediately and go to a professional repair shop. Don't push through it, or the engine might be completely ruined, making repairs even more expensive. For prevention: choose good fuel quality, regularly clean throttle valve carbon deposits, and always pay attention to the car's condition.
I've been driving for over a decade and have encountered engine knocking issues multiple times, feeling anxious when hearing that thumping sound. Usually, this is caused by detonation from low-octane gasoline or aging spark plugs failing to ignite properly. My solution back then was simple: switching to higher-octane gasoline made the abnormal noise disappear. However, if the knocking intensifies or power weakens, it might indicate internal mechanical failures like piston ring wear, requiring immediate stop and a visit to the repair shop. Never attempt DIY disassembly—only professional tools can pinpoint the issue. For prevention, I regularly: change engine oil every six months and have mechanics listen to the engine during maintenance to detect potential problems early, saving both money and hassle, as repairs can cost anywhere from hundreds to thousands.
Before every drive, I make it a habit to listen to the engine starting sound. Knocking, which resembles a small hammer tapping the cylinder wall, is often caused by carbon buildup or insufficient combustion of the air-fuel mixture. Don’t panic—safely pull over and check simple factors first: whether the gasoline is of low octane rating or if the spark plugs are worn out. If these issues are resolved, you’re good to go; otherwise, head to a repair shop for a comprehensive inspection. Prevention tips: use high-quality gasoline, avoid aggressive acceleration, and maintain steady driving. My car once had slight knocking, but it became quiet after carbon cleaning. Never ignore unusual noises—timely action ensures safety and peace of mind.
