My dad has an '02 2500HD, DA, 4x4 that he purchased new (one of the reasons I fell in love with the D/A
). I was talking to him tonight and he described an "observation" with the truck. Since he took initial delivery, he experiences a phenomena with the oil staying at the full mark for about 3500 miles and then, it just starts dissappearing. About every 300 miles, it goes down another hash mark on the dip stick.
Now, you gotta know my dad. Meticulous! Logs all maintenance and fuel fill-ups with his vehicles. Takes extremely good care of his vehicles and he can tell you any changes in sound, vibration, performance from week to week. I have verified the following:
<UL>
<LI>Always has used Shell Rotella 15W-40</LI>
<LI>Always checks oil while parked on flat surface</LI>
<LI>Checks when engine is cold for consistency (usually in the morning)</LI>
<LI>This has occurred for almost two years now in all weather and driving conditions (cold/warm/hot/dry/humid)</LI>
<LI>Method of pulling and re-seating dip stick is consistent</LI>
<LI>No oil leaks whatsoever</LI>
<LI>The truck now has about 27,000 miles on it</LI>[/list]
What else is there? After approx 3500 miles, does it just start burning oil? (No)
Do the chemical properties of the oil change to the point that it burns or otherwise consumes or discharges oil (maybe, but unlikely)
Why would this not be a consistent consumption of oil througout life of the oil?
We thought about contacting GM or Shell but I offered to drop this out here to you folks first and see what you could suggest. I am new to diesels and this forum has provided a ton (or maybe 3/4 ton
) of information. Great site!
Thanks in advance!!!!

Now, you gotta know my dad. Meticulous! Logs all maintenance and fuel fill-ups with his vehicles. Takes extremely good care of his vehicles and he can tell you any changes in sound, vibration, performance from week to week. I have verified the following:
<UL>
<LI>Always has used Shell Rotella 15W-40</LI>
<LI>Always checks oil while parked on flat surface</LI>
<LI>Checks when engine is cold for consistency (usually in the morning)</LI>
<LI>This has occurred for almost two years now in all weather and driving conditions (cold/warm/hot/dry/humid)</LI>
<LI>Method of pulling and re-seating dip stick is consistent</LI>
<LI>No oil leaks whatsoever</LI>
<LI>The truck now has about 27,000 miles on it</LI>[/list]
What else is there? After approx 3500 miles, does it just start burning oil? (No)
Do the chemical properties of the oil change to the point that it burns or otherwise consumes or discharges oil (maybe, but unlikely)
Why would this not be a consistent consumption of oil througout life of the oil?
We thought about contacting GM or Shell but I offered to drop this out here to you folks first and see what you could suggest. I am new to diesels and this forum has provided a ton (or maybe 3/4 ton

Thanks in advance!!!!