# Timing Belt vs. Timing Chain: When to Replace

> Does your car have a timing belt or a chain, and when does it need service? Why a snapped belt can total an engine, and how to avoid it.

*Tab Motors Auto Repair | Exxon, 4035 Old Dominion Dr, Arlington, VA 22207 · (703) 243-3080*

Buried inside your engine is one of two things keeping everything in sync: a timing **belt** or a timing **chain**. Which one you have changes your maintenance completely, and getting it wrong can mean a totaled engine.

## The key difference

A timing **belt** is made of reinforced rubber and *must* be replaced on a schedule, commonly every 60,000 to 100,000 miles depending on the vehicle. A timing **chain** is metal, runs in oil, and is designed to last far longer, often the life of the engine, though it's not entirely maintenance-free.

## Why a broken belt is a disaster

Most modern engines are "interference" designs, meaning the valves and pistons share the same space at different moments. If the timing belt snaps, that timing is lost, pistons slam into open valves, bending them and sometimes damaging more. The result is a repair that can cost several times what a scheduled belt replacement would have. That's why the interval is not a suggestion.

## Replace the water pump too

On many engines the water pump is driven by the timing belt and sits right behind it. Since the labor to get in there is the expensive part, replacing the water pump, tensioner, and idlers at the same time as the belt is the smart, economical move.

## Not sure which you have?

Tell us your year, make and model and we'll tell you exactly, and we won't sell you a belt job on a chain-driven engine. If you're near the interval or bought the car used with no records, get it checked. See our [timing belt & ignition](../services/timing-belt-ignition.html) service, or call (703) 243-3080.

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Call (703) 243-3080 or visit TAB Motors | Exxon at 4035 Old Dominion Dr, Arlington, VA 22207.