timing chain

Also called timing chains

Draft: this page has not had its final check yet, so check the sources behind anything you rely on.

A metal chain that does a timing belt's job. It outlasts a belt, but it wears faster when the oil is neglected or its guides or tensioner fail.

The story

History: facts, each with the kind of source it rests on

Metal timing chains spread from the 1990s so that engines no longer needed a rubber belt changed on a schedule. The chain itself wears little, but poor lubrication or a failed tensioner or chain guide can wear it out fast or break it early. A published reference

A training manager at Snap-on Diagnostics writes that what mechanics call a stretched chain is really wear in the chain's parts. The chain grows longer and moves the camshaft timing, and the most common cause is missed oil changes and the wrong oil. Vehicle Service Pros

Found on

Every generation on the site whose dossier or engine names it

Watch out for

Reputation: what owners and the press report. Tap one to see what to check.

  • A rattle from the front of the engine Wherever it is fitted One source so far

    What to check: Listen at the front of the engine at a cold start for a rattle.

    A worn chain system rattles from the front of the engine as a warning, where a rubber belt gives none.

    A published reference

  • A worn, lengthened chain Wherever it is fitted One source so far

    What to check: Look for a check engine light, ask for the codes to be read, and ask for the oil change records.

    Snap-on Diagnostics lists a check engine light, hard starting or no start, noise, misfires and low power as signs, and says the changed timing usually sets codes for the camshaft and crankshaft sensors not agreeing.

    Vehicle Service Pros