Losing Oil

[snowman]

I have a stock 5. 9 which has started using oil between changes. Mileage is low (28K) and I change the oil at 4-5K mile intervals with Rotella T. I am dropping from the top of the full mark to the halfway mark on the dipstick between changes. The motor and radiator fluid is clean, and I always check at the same spot in the driveway. My lasy 5. 9 (2000 model) never used oil at all. Any ideas?

 

[SierraRam]

Just curious, do you re-check the level after you change the oil and have driven it a short while? If the level is actually dropping it either has to go on the groung, into the coolant system or out the exhaust. I hope its not a major issue for you.

 

[lmills]

Not trying to question you ability, but are you putting the full 12 quarts in that the 3rd gens call for? Cause the 2nd gens like you previously had only used 11 quarts

 

[snowman]

Yes, I do recheck the next day after driving, and yes 1qt in the filter and 11 in the crankcase. I do have soot on the back bumper, but have pretty much always had that as well.

 

[steved]

What service is the truck doing... towing, high speed highway, etc??



I found that Rotella CJ-4 15w40 would seemingly "boil off" under hard use and look as though I had lost almost a quart of oil. The oil still indicated good wear and suitable for continued use, but did show signs of thickening (which I late attributed to boil off from running hard/hot).

 

[snowman]

Mostly light loads. It did show the most change towing 5000 pounds for 600 miles at 65mph. I do not tow often and most highway miles are at or below the posted limit. I rarely do over 70mph.

 

[steved]

That stint of towing is probably what did it... you are probably having the same thing happen as I did.