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Old 01-20-2019, 11:04 AM
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jhodg5ck jhodg5ck is offline
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Quote:
Originally Posted by 300SDiesel View Post
Bought a 1990 420SEL a couple of months ago with 96,500 miles. The PO had replaced the timing chain and guides back in 2004 at 73,000 miles. I was worried about the guides as it has not been a lot of miles, but 15 years has elapsed. Doing a bunch of research and look at videos made me very worried that the guides would be bad.

I borrowed my airplane mechanics’ borescope and took a look inside the motor. Luckily the guides still are mostly white with a slight discoloration. What does the group think?

Thanks for your input.

Stephen
I think you'll be OK. Those haven't turned dark brown yet. They likely haven't seen many heat cycles either. Make sure those cam oiler tube clips look Good..not everyone changes them when they do TC & rails


Also make sure what ever oil you are running hasa zinc count 1200 ppm or Above! The rocker/cam geometry creates a LOT of force at that mating surface.

Jono

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