How to Identify Connecting Rod Bearing Noise?
2 Answers
Methods to identify connecting rod bearing noise: 1. Judge by different sounds emitted by the engine: When listening outside the engine, the sound is short and solid, like "tap, tap"; 2. When listening at the oil filler port, the sound is clear and loud, like "clang, clang"; 3. If the engine changes from idle to medium speed, the sound becomes clearer, with continuous knocking, and as the speed increases, the knocking becomes more prominent; 4. If the single-cylinder cut-off method is used for inspection and the sound weakens or disappears, it indicates that the connecting rod bearing of that cylinder is making noise; 5. If the sound is mixed, appearing as "jingle, jingle" or "clatter, clatter", the cut-off method can also be used for inspection. If the sound weakens after single-cylinder cut-off, and then weakens or disappears after double-cylinder cut-off, it indicates that multiple connecting rod bearings are worn and loose; 6. Regardless of whether the engine temperature is low or high, or at any speed, if there is a severe and irregular "clang, clang" sound, and the cylinder head vibrates strongly, and the results are the same during cut-off or re-ignition tests, it can be concluded that the connecting rod bearing alloy layer is overheated and melted, and immediate disassembly and repair are required.
As a seasoned driver with over twenty years of experience, I've encountered connecting rod bearing noise issues several times. The sound is a crisp 'clack-clack' knocking, especially noticeable during cold starts or acceleration. It's more audible at low RPMs, and the sound frequency increases when stepping on the gas. Checking the oil level and quality is crucial—if the oil is too dark or insufficient, top it up immediately. Once, I ignored it, leading to a major engine overhaul and significant losses. So, I remind everyone to regularly monitor noise changes. If you hear such rhythmic sounds from the engine's bottom, take it to the workshop to check for excessive clearance or poor lubrication. Don't delay to prevent the problem from worsening and affecting driving safety.
