How Long Do Timing Chains Last And Do They Need To Be Replaced?

The answer to the question about how long timing chains last and whether they need to be replaced has two possible answers. It all depends on your answer to this question: Do you maintain your car properly?

If your answer is yes, congratulations! Your timing chain should last the life of your car without giving you any problems whatsoever — as it is intended to. Regular oil changes and servicing at the manufacturer's recommended intervals should keep your timing chain clean, cool, and intact without any need to replace it. Whether you have an SOHC or a DOHC engine, you have nothing to be concerned about.

But if your answer is no, watch out! In addition to many other problems that can result from neglecting your vehicle's care, your timing chain could deteriorate and cause a lot of damage to your engine. This is a near-guarantee of a very expensive repair job, on top of replacing the timing chain itself. Worst-case scenario, the pistons could make contact with the valves and destroy the engine. Understanding the role of your timing chain in your engine's health will help explain why proper car care is so important for trouble-free driving.

Your timing chain has one primary function: synchronizing the workings of the bottom of your engine with those of the top. On the bottom, the timing chain is connected to the crankshaft, which is controlled by the connecting rods and the pistons. On the top, the timing chain is connected to the camshafts, which control the intake and exhaust valves.

When operating as intended, the timing chain is responsible for the timing of the valves opening to let air (and sometimes fuel) into the cylinders, the pistons compressing the air-fuel mixture, the exhaust valves opening to remove the byproducts of combustion, and repeating the process thousands of times each minute. The timing chain is lubricated by the engine oil, so regular oil changes help it to last.

It should be noted that every vehicle does not have a timing chain. Some have a timing belt, which do wear normally and require replacement at specified intervals (check your owner's manual). 

Some warning signs of a timing chain that may be going bad include rattling noises. This can be due to a failure of the nylon noise-prevention guides on the chain or the tensioner that keeps the chain taut. If the chain is not damaged, it will not need to be replaced. 

Other signs of a more serious problem include an engine that won't start or starts with difficulty, shaking or vibration when idling, an engine misfire, generally poor engine performance, or an illuminated Check Engine light. If any of these happen, see your mechanic right away!