What Happens If Your Timing Belt Snaps?

Your timing belt keeps the top and bottom of your engine working in time with each other. It's just a rubber belt - but when it breaks, it usually takes a lot of the engine with it.

This short video from driven by science shows what happens inside the engine when one snaps.

Video by driven by science (@driven_by_science) - all credit to them.

Why it's so serious. In nearly all diesels, the valves and pistons move through the same space, and the belt is the only thing keeping them apart. If it breaks, they hit each other - bending valves and often ruining the cylinder head. That usually means a repair costing thousands, and on an older car it can write it off.

When to change it. Makers give an interval in both miles and years - whichever comes first. The rubber ages even if you barely drive, so a low-mileage car can still be overdue. It varies a lot, so check what yours needs.

Don't wait for warning signs. You might hear a ticking or rattle, or find it hard to start - but many belts fail with no warning at all. That's why you change it on time rather than waiting for symptoms.

Change the water pump too. On many engines it runs off the same belt and sits right behind it. The hard part - getting to it - is already done, so it's worth doing both at once to save a second labour bill later.

Not sure when yours was last changed? Bring it in and we'll check it against your car's age and mileage - no obligation.