Timing Belt Repair: Why It Matters

What the timing belt does

The timing belt keeps the engine’s valves and pistons in time. It links the crankshaft at the bottom of the engine to the camshaft or camshafts at the top, so the valves open and close at the right moment.

Belt or chain?

Some engines use a timing belt and others use a metal timing chain. Check your owner’s manual: if it lists a timing belt interval, your engine has a belt. A chain is generally built to last longer, but it can still wear.

Why failure is serious

In an interference engine, the valves and pistons occupy the same space at different times, and the belt keeps them apart. If the belt breaks, they can collide, bending valves and sometimes damaging the pistons, cylinder head or camshaft. A broken belt will also stop the engine immediately. A belt often gives little or no warning, which is why following the interval matters more than waiting for symptoms.

When to replace it

Check your owner’s manual for the timing belt interval, which differs by vehicle and may be based on both mileage and age. Many shops replace the water pump and tensioner at the same time when they are driven by the belt, since the labor overlaps.

Signs of trouble

• Squealing, whining or ticking from the front of the engine (a worn tensioner or idler bearing)
• Oil leaking near the belt cover
• Difficulty starting or a rough-running engine
• A check engine light

Next step

Our ASE-certified technicians can inspect your vehicle and explain your options. Book at whichever of our shops is most convenient.