What Sound Does Engine Abnormal Noise Make?
3 Answers
Engine abnormal noises include the impact sound between the piston top and cylinder head. Below are the specific manifestations of engine abnormal noises: Piston Slap Fault: If a "ticking" knocking sound is heard from the upper part of the engine, with the sound being rhythmic and its frequency increasing as the engine speed rises, this abnormal noise mainly originates from the impact between the piston top and the cylinder head. If a "clanking" or "ticking" knocking sound is heard from the side of the engine block during operation, it usually indicates a piston slap fault in the engine. Other Causes: If the engine emits a "clanking" sound, it indicates insufficient lubrication between the cylinder and the cylinder liner. If the piston slap sound is a "ticking" noise, it likely suggests issues such as piston wear or out-of-roundness.
Once while driving on the highway, I suddenly heard a rapid 'tat-tat-tat' sound from the engine bay, like a small hammer quickly tapping on sheet metal. Later inspection revealed excessive valve clearance. Actually, engine abnormal noises come in all varieties: valve noise resembles metal beads bouncing; worn piston pins produce crisp and dense 'click-click' sounds; if the timing chain is loose, you can hear a 'clattering' chain friction noise at idle. The most dreaded sound is a dull 'thud-thud,' like someone beating a drum inside the engine—this could mean the connecting rod bearings are failing. It's recommended to record any new abnormal sounds and play them for the mechanic during repairs—it's far more effective than verbal descriptions.
The worst thing about driving an old car is hearing the engine 'sing.' My decade-old car loves to perform: during cold starts, it squeaks like a little bird—the mechanic said it's due to aging belts. When accelerating hard, it suddenly makes a clattering noise, like shaking a coin jar, which turned out to be engine knocking. The scariest was that time I floored the gas and heard a metallic tearing sound—I immediately backed off and took it in for inspection, only to find out the exhaust gasket had blown. These sounds are like the car's Morse code; understanding them can save you big money. Remember, metallic grinding noises are more dangerous than rubbery squeals—the latter might just mean replacing a belt, but the former could mean major repairs.
