M42 Timing chain life span?

["Michel Drainville" <MDrainville@xxxxxxxxxxx>]

Does someone know at what interval a timing chain must be replaced?

Is it something that needs to be replaced as a preventive maintenace like a
belt or it should be replaced only when it rattles or cause drivability
problems?

I'm asking that because yesterday I changed my chain tensionner. The
tensionner suddently compressed itself into the body of the tensionner, and
was stuck fully compressed. That tensionner is not very old. It was
replaced 50000km (30000mi) ago.
Could it be the timing chain being too slack, that pushed the tensionner
violently and caused it to jam fully compressed? My enigne has
183000km(109000 mi).

Now I have a new tensionner and the engine runs fine, but I would like to
prevent catastrophic failure like broken timing chain or chain guide
collapsing etc.

Thanks

Michel Drainville
www.geocities.com/bmw_318ic

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