What are the consequences of a car timing chain skipping teeth?
4 Answers
The consequences of a car timing chain skipping teeth are: the acceleration may feel less powerful than before, fuel consumption may increase, and the engine sound may become slightly muffled. The functions of the timing chain are: 1. To drive the engine's valve train, ensuring that the intake and exhaust valves open and close at the appropriate times; 2. To guarantee that the engine cylinders can properly intake and exhaust air. The replacement method for the timing chain is: 1. Remove the valve cover and then the timing chain housing; 2. Rotate the crankshaft to align the first cylinder at top dead center and secure the crankshaft with the fixing bolt; 3. Rotate the intake and exhaust camshafts; there are grooves at the rear of the camshafts—align these grooves evenly; 4. Remove the old chain and install the new one; 5. Ensure there is no gap at the crankshaft position sensor during installation to avoid triggering fault codes.
A friend's car broke down because of this issue just two days ago, and I only understood the problem after following him to the repair shop. The scariest thing about chain skipping is that the valves and pistons can collide—just a 'click' and they hit each other. At best, the valves bend and you'll need to open the cylinder head; at worst, the piston cracks, the connecting rod deforms, and the entire engine could be totaled. My friend's car suddenly started shaking at idle, lacked power when accelerating, and made a rattling noise—if driven further, it would have needed a major overhaul. The mechanic said older cars are especially prone to this issue—whether it's a loose chain or a faulty tensioner, both are dangerous. If you hear any unusual noises, getting it checked immediately is the right move.
Having repaired cars for over a decade, I've encountered numerous cases of timing chain skipping. The most disastrous scenario is engine timing misalignment. When the piston moves upward while the valves haven't retracted, the hard collision can bend valve stems. In severe cases, pistons crack and cylinder walls get scratched, rendering the engine irreparable. Once, a car owner noticed power loss during acceleration accompanied by metallic knocking sounds but insisted on driving to the shop. Upon disassembly, we found nine out of sixteen valves bent. Chain skipping usually occurs due to tensioner failure or guide rail wear, especially in vehicles that produce rattling noises during cold starts – these require extra vigilance.
New car owners, take note: chain skipping is no small matter! The engine internals are like a precision clockwork; misaligned teeth can cause valves and pistons to collide. The symptoms are obvious: sudden loss of acceleration, backfiring from the exhaust, and the dashboard warning light coming on. Once, my car made a clattering noise during a cold start, and I immediately sent it for inspection—sure enough, the tensioner had insufficient oil pressure. The mechanic said if I had driven it any longer, a top-end overhaul would have cost at least 8,000 yuan. Regularly checking the chain tensioner is crucial, especially for cars with over 100,000 kilometers.
