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Caught a guy at the parts counter ranting about synthetic oil in older Cummins

He was saying how he flushed 15 quarts of Rotella through his 5.9 after 200k miles of conventional and it started leaking from every seal. Made me realize I've been babying my rebuild with fancy oil when the old stuff probably kept the gaskets swollen. Any of you guys run conventional in high-mileage engines on purpose?
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2 Comments
wyatt_garcia
Thick conventional keeps those old seals happy. @hayden_martin29 I'd be curious if switching back actually plugged things up or just slowed em down.
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hayden_martin29
Did you try going back to conventional to see if it stops the leaks?
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