What Causes the Clanking Noise During Cold Start?

[DiAva]

Cold start clanking noise can be attributed to the following reasons: 1. If there is a clicking sound within the first half minute that disappears afterward, this is usually caused by the expansion of the catalytic converter as it heats up, which is normal; 2. A loud clicking noise during cold start is mostly due to issues with the engine's timing system, such as wear, elongation, or loosening of the timing belt or chain, or the failure of the chain tensioner to maintain proper tension; 3. If the noise occurs only when the air conditioning is turned on, it may be due to friction in the air conditioning belt; 4. If the noise is present only during the initial moment of cold start, it could be a fault in the starter motor, primarily caused by poor return of the starter gear, inadequate lubrication of the one-way clutch, or slow return of the gear being dragged back by the flywheel. This phenomenon is more common in winter.