Timing belt failure destroys engines. Replacement costs £350–900 but the alternative is a £3,000–8,000 engine rebuild. Here is the full cost breakdown and why skipping it is never worth it.
This Repair Cost Guide guide combines structured analysis — verdicts, risk scoring and cost ranges where we have enough data — with real fault cases pulled directly from MyCarFault's reporting database, so the guidance below reflects what owners actually experience rather than manufacturer specifications alone. Background and analysis come first, followed by the linked fault reports and related guides you can jump to directly using the links above.
The timing belt (also called cambelt) synchronises the crankshaft and camshaft, controlling when the valves open and close in relation to piston movement. On interference engines — which includes most modern cars — if the belt snaps, pistons and valves collide, bending valves and destroying the engine. The repair cost after belt failure runs £3,000–8,000 for a rebuilt or replacement engine. Preventive replacement costs £350–900. The arithmetic is simple.
Check your service history or handbook. Timing chains generally do not have a replacement interval. Belts are listed in the service schedule. Your garage can confirm by checking the engine.
You can inspect it visually if accessible, looking for fraying, cracking or glazing. However, a belt can look serviceable and still snap — internal cords degrade invisibly. Do not extend beyond the manufacturer interval based on visual inspection.
The belt risk increases significantly. Many failures happen within 10–15,000 miles of a missed interval. If in doubt, replace it.