When Should You Change Your Timing Belt?

What does the timing belt do?

The timing belt (or cam belt) synchronises the rotation of the crankshaft and camshaft so the engine's valves open and close at exactly the right time. Without it working correctly, the engine can't run. If it snaps or skips — the results are usually catastrophic.

What happens if it breaks?

On most engines (called "interference engines"), a snapped timing belt causes the pistons and valves to collide. The result is bent valves, damaged pistons, and potentially a destroyed engine. Repair costs can run into thousands. In many cases, it's cheaper to replace the car.

Even on non-interference engines, a snapped belt means the engine stops immediately — wherever you are.

When should it be replaced?

Most manufacturers specify replacement every 60,000 to 100,000 miles, or every 4 to 5 years — whichever comes first. The time-based interval is important: the belt degrades even if you don't drive many miles.

Check your car's handbook for the exact interval. If you've bought a used car and don't know the belt history, assume it needs doing and budget accordingly.

What else should be replaced at the same time?

The water pump is usually replaced alongside the timing belt because it's driven by the same belt and requires the same labour to access. Replacing it at the same time adds a small cost to parts but saves significant labour cost if it fails later. The tensioner and idler pulleys should also be replaced as a kit.

Is there any warning before it fails?

Usually no. Timing belts rarely give obvious warnings before snapping. The only reliable protection is replacing on schedule. Some cars have a timing chain instead — chains last much longer and don't need regular replacement, though they can stretch over time.

Not sure whether your car has a belt or chain, or when it was last done? WhatsApp Reliance Autos — we'll check the history and advise honestly.