Would it ruin the engine on 2003 Kia Sedona if timing belt broke?

Yes, a broken timing belt can cause severe engine damage in the 2003 Kia Sedona. The timing belt is a crucial component that synchronizes the movement of the crankshaft and camshaft, ensuring that the pistons and valves operate at the correct intervals. When the timing belt breaks, it disrupts this synchronization, causing the valves to hit the pistons. This collision can result in bent valves, damaged pistons, and potentially other engine components, leading to extensive and costly repairs. Therefore, it's essential to follow the manufacturer's recommended maintenance schedule for timing belt replacement to prevent such catastrophic engine failures.