
Car engine abnormal noises may be caused by the following reasons and solutions: 1. Reason: Engine mount aging or loosening. The engine mount, which connects the car body and the engine, plays a role in fixing the engine. Once the mount ages or loosens, the engine will produce abnormal noises. Solution: Replace the mount. 2. Reason: Piston slap. If the car makes a clanking noise, it indicates poor lubrication conditions, and the piston collides with the cylinder wall during engine operation. Solution: Replace the engine oil. 3. Reason: Dirty throttle or excessive carbon deposits in the fuel injector. Solution: Remove engine carbon deposits, clean the throttle, and replace the oil pad and spark plugs.

My old car has been running for ten years, and I've encountered engine abnormal noises several times. Sounds are crucial indicators – a ticking noise might point to valve clearance issues, a knocking sound could suggest loose connecting rod bearings, while a humming noise may indicate belt wear. Never ignore abnormal noises; I usually check the oil level immediately since low oil can cause dry friction and produce sharp screeching sounds. If the noise suddenly appears on the highway, I slow down, pull over at a service area, shut off the engine, and inspect under the hood for oil leaks or loose pipelines. Last time, a ruptured vacuum hose caused a hissing sound – I temporarily fixed it with tape before driving to the repair shop for pipe replacement. Metallic knocking sounds are the most dangerous; in my case, a spark plug electrode broke off and nearly damaged the piston. Remember, minor issues left unfixed can escalate into major troubles.

Engine noise is like a person coughing, you need to identify the root cause. I've figured out a few inspection steps myself: first, listen to the type of sound, whether it's metal friction or plastic collision; then feel the engine vibration—if it shakes severely at idle, it's likely due to worn engine mounts; next, check the warning lights, and never ignore any warning symbols. The most common issue in daily use is the squeaking of the belt, which can be temporarily relieved by spraying some belt wax, but it's only a temporary fix. Last time, my car made a clanking sound during cold starts, and it turned out the timing chain had stretched. The mechanic said delaying repairs could bend the valves. If you suddenly hear unusual noises while driving, turn off the AC and audio to carefully identify the location—the pulley area and cylinder head are the most prone to problems. If you really can't figure it out, recording a video with your phone and showing it to a repair shop is the safest bet.

When dealing with engine abnormal noises, I follow several basic principles: First, distinguish between normal noise and abnormal sounds. For example, the ticking sound of a direct injection engine is actually normal. When real problems occur, first check the three fluids—engine oil, coolant, and power steering fluid, as insufficient fluid can cause hydraulic lifter noise. Abnormal noises when the engine is hot are usually due to expansion components, while cold engine noises are mostly lubrication issues. A slipping belt will produce a screeching sound, and bearing damage will cause a humming noise. If you hear a sound like a small hammer hitting metal, you should immediately check the crankshaft and connecting rod. I once replaced the alternator belt and tensioner pulley myself, saving 300 yuan in labor costs, but for precision areas like the valve chamber, it's more reliable to leave it to professional technicians.


