The Anatomy of Healthy Cars: A Service and Repair Blog

What Can Cause a Timing Chain to Break?

by Brittany Marshall

Your vehicle's engine is a complex and intricate system that requires many parts to work together harmoniously. One of the essential components of this system is the timing chain. It connects both the crankshaft and camshaft and ensures that the valves of the engine open and close at the right time. But sometimes, this critical component can break, causing significant engine damage. How can this happen, and what should you do it prevent it?

Lack of Maintenance

One of the main reasons timing chains break is due to a lack of maintenance. Regular oil changes keep the engine lubricated, preventing the chain from wearing down and breaking. If the oil becomes dirty or sludgy, it won't effectively lubricate the chain, causing it to wear out. Not changing the oil filter, changing the oil too infrequently, or using the wrong oil type can also damage the chain.

High Mileage

As your vehicle racks up more kilometres, various parts inevitably wear down. The timing chain is no exception. Over time, the chain stretches, causing it to become loose and eventually fail. If you notice any strange noises coming from your engine, it could be a sign that your chain is starting to wear out.


Another reason the timing chain can break is if the engine overheats. High temperatures can cause the chain to expand excessively, becoming slack too soon. This scenario puts added strain on the components that manage the chain's tension. And, If the chain is under too much load, it can snap, leading to engine failure.

Faulty Tensioner

The timing chain tensioner helps to keep the chain under the right amount of tension. But, if it malfunctions, the chain can become loose, increasing the likelihood of failure. If the tensioner becomes worn or damaged, it won't adequately manage the tension, leading to unexpected wear to the chain and other components, ultimately leading to a chain that fails.

Poor Quality Parts

If your vehicle doesn't have original equipment manufacturer (OEM) parts or if the parts you choose are of poor quality, the chain will not perform as intended. Components that aren't designed specifically for your vehicle will not fit correctly or install accurately, leading to problems. Low-quality parts can wear down faster than high-quality ones, and the chain could snap sooner than expected.

What to Do Next

A timing chain failure is never a good thing, leading to significant engine damage. Many factors can cause the chain to fail, including lack of maintenance, high mileage, overheating, faulty tensioner, and low-quality parts. But if you perform routine maintenance and take the vehicle to a mechanic at the first signs of an issue, you can mitigate a lot of these dangers.

Talk to local mechanics to learn more.