How common are timing chain stretching problems? Is it only on V8s?

Does the chain really jump a teeth when it gets stretched?

I remember on my 318ic (M42 engine), the hydraulic timing chain tensionner was going bad every 2-3 years, and the chain was completly loose, rubbing on the chain cover at idle with a scary noise, but it never jumped a theeth. May be a different design.

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