I'm running a 5-40 synthic and it's very runny. This is the first time I've run a synthic oil and it looks like the oil level is a little higher than when I filled it a Thousand miles ago. I fear maybe the injection pump is leaking into the oil. I had the same problem on my grandfathers tractor that ended in the death of the motor. Funny thing is it was leaking/ burning oil at the same rate as the injection pump leaked.

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84 300sd 2.47 dif 360k
26 mpg needs lots of love
given to me in pitty

89 civic hatchback auto 140k
33mpgs soon to be low to mid 40's
been in the family since mile 1

85 300d with unknown knock. driven over 30k with knock and still going. sold for $800