Almost all Benz & BMW engines use these plastic timing chain rails. The fault is in the tensioner on MB V-8's, if they fail then chain damage is certain. Most of the time a rattle on start-up is noticed well before failure. ALSO turning the engine backwards will cause the rails to fail! Many times failure happens after a water pump replacement as many techs turn the engine backwards to access bolts! OF course if they knew better THAT wouldn't happen. Tensioners fail due to oil change frequency. Or should I say lack of IT.

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MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
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190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
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