I can help you on the M117 engines!

Please check chain stretch by pulling a valve cover and check the oil tubes.. upper guide rails. I think you should do it every 30k after. I think a chain is fairly cheap relative to a valve job plus a broken chain. Most mechanics recommend 100k intervals regardless of engine model.

And if it was my reputation- I'd be saying the samething! I don't think M103 chains last the life of the engine... maybe to the first valve job or so.


Michael

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Michael McGuire
83 300d
01 vw A4 TDI
66 Chevy Corsa
68 GMC V6 w/oD
86 300E