What are the causes of abnormal noise during cold start?
2 Answers
Cold start abnormal noise is caused by: 1. The internal gears of the starter losing lubrication, becoming stiff or stuck, affecting timely gear reset; 2. Dirty starter internals with ineffective lubricant; 3. Low temperatures causing rubber components in the suspension to harden and changes in the brake disc and pad surfaces, resulting in noise during startup; 4. Excessive wear of brake discs and pads. Solutions for cold start abnormal noise include: 1. Timely lubrication of starter internal gears; 2. Cleaning the starter internals; 3. Regular inspection and replacement of brake discs and pads; 4. Noise disappearing as engine temperature rises.
Having driven for decades, the most common cause of abnormal noise during cold starts is definitely issues with the belt system. Especially the timing belt or AC belt—if they're aged or loose, the belts contract in cold temperatures during startup, causing a squealing sound that can be quite alarming. Starter motor problems are another culprit; if the gears are worn, you'll hear a grinding noise during ignition, like teeth clashing. Let me mention engine oil—it tends to thicken in winter, slowing lubrication when cold, which can also lead to strange metallic friction sounds. Ignoring this can make things worse over time. I recall a friend’s car burning out its starter motor due to this, costing a fortune to repair. My usual advice is to try changing the oil first; if that doesn’t work, check the belt tension and starter motor condition—don’t wait until the noise worsens. Regular maintenance with added lubricant as a preventive measure is even better.
