BMW M4 Timing Chain Tensioner Replacement Cost

When the timing chain tensioner has failed, there may be damage to the timing chain guide rails of engine front cover, so the technician may recommend further inspection or changing the oil to inspect for debris.

For engines with more than one timing chain tensioner, they should be replaced as a set.

A worn timing chain tensioner will allow the timing chain too much slack, and this may lead to a slapping noise - especially on cold start-up.

Timing chain tensioner wear may cause the check engine light to illuminate, and the engine may run rough, hesitate, or stall.

The sound of timing chain slap is similar to a tapping lifter at startup, so many times they are not replaced because the sound goes away after a few moments.