Timing Belt vs Timing Chain: What Every Car Owner Should Know

The timing belt or chain is one of the most important parts of your engine, and one of the most expensive to ignore. Knowing which one your car has could save you from a very costly breakdown.

What it does

Inside the engine, the crankshaft (moved by the pistons) and the camshaft (which opens and closes the valves) must turn in perfect time with each other. The timing belt or chain connects them and keeps them synchronised.

Timing belt

A timing belt is made of reinforced rubber with teeth. It's quiet and cheaper to make, but it wears out over time.

• Replacement: Manufacturers set an interval based on distance or age. It's often somewhere between 100,000 and 160,000 km, but it varies widely, so check your manual.

• Heat matters: Rubber ages faster in hot climates, so age counts as well as mileage.

• Usually done with it: The tensioner, idler pulleys and often the water pump, since they're behind the same covers.

Timing chain

A timing chain is metal, like a bicycle chain, and runs inside the engine bathed in oil. Chains are designed to last much longer, often the life of the engine, but they can stretch or their guides and tensioners can wear out.

• Warning signs: A rattling noise at start-up, check engine light with timing-related codes, or rough running.

• Biggest enemy: Old, dirty or low engine oil. Regular oil changes are the best protection.

What happens if it fails

In many engines, called interference engines, the valves and pistons share the same space at different times. If the belt breaks, the valves can hit the pistons, bending valves and causing major engine damage. In other engines the car will simply stop and won't restart.

Signs of a worn timing belt

• Ticking noise from the front of the engine

• Engine misfires or runs rough

• Oil leaking from around the timing cover

• Cracks or missing teeth (seen during inspection)

Often, there are no warning signs at all before it snaps, which is why sticking to the replacement interval is so important.

Not sure which you have?

Check your owner's manual, or ask your mechanic. If you've just bought a used car and don't know when the belt was last changed, it's wise to treat it as due.

Need help with this? RCJ Mobile Mechanics comes to you in Portmore, Spanish Town, Kingston, St. Andrew and across St. Catherine. Call or WhatsApp (658) 207-6565 or book a mechanic online.