Oil Leaking Duramax

[88grayghost]

I have a 2002 GMC 3500 4x4 dually with the Duramax diesel engine. There is only 25,000 miles on the truck. The first time I used the truck to pull my 10,000lb fifth wheel camper ( after only going approximately 200 miles ) the truck leaked almost 2qts of oil, covering mainly the right side of the engine and under carriage. After getting it back home, the dealers diagnosis was there was a bad injector. This caused fuel to get in the oil creating pressure and blowing the oil out a vent tube. This makes sense to a point, however, I don't understand why the truck was down almost 2qts of oil. I think the truck should have shown the oil level to be over full. The dealer isn't giving me a hard time with this at all, however I don't understand their logic in this diagnosis. My concern is that we have a long trip planned in a few weeks and really don't want to have truck trouble then. Any input as to whether the dealers assessment of my problem is correct or not would be appreciated.

[coyotekid]

This might be a long-shot, but oil analysis should show that your oil is "washed out" by having large quantities of diesel in the remaining oil.