What causes the grinding sound when starting a cold engine?

[VanWyatt]

Cold start grinding noise may be caused by the timing chain lacking lubrication during startup, which generally does not require repair. The reasons for grinding during startup are: 1. Weak battery; 2. Issues with the starter itself. Methods to check the fault: 1. Inspect whether the timing belt is broken or has frayed edges; 2. Check if the starter is misaligned or if the belt connected to the starter is aged or curled; 3. Examine the idle speed motor. It's best to determine whether the noise is from within the cylinder block. If not, it can generally be confirmed to be related to the vehicle's starting system.