I have an 03 LB7, this AM when I went out to get the truck, I had a two foot puddle of oil underneath the truck, appeared to be coming out of the LH side of the engine. It did not appear to be diluted oil, but pure oil, checked the oil level and it was down ~ a half quart. Truck is running great, no problems that I know of, has less than 15K miles. I have an appointment in the AM with the local dealer and was wondering if anyone else has experienced this problem and if so, what caused it, or if anyone has any idea what caused this. Would like to be prepared with as much info as possible when I talk with the dealer.

Check your oil filter to make sure it is tight.

Yes, I would say check the filter. Did you just recently change the oil? If so did you make sure you got the old filter seal off with the old filter?

Well I can't believe it, since it was due an oil change, I decided to do that before I took it to the dealer. The oil filter was loose, since I was the one that had previously changed the oil, I know I tightened the filter properly. So I'm completely baffled, the instructions on the BOM filter says to hand tighten and then another half turn, which I have been doing. Do these Duramax's have some unusal vibration/resonance that over time would cause the filter to loosen? Guess I better perodically check it from now on............

this same thing has happen to me 3 oil changes in a row lose oil filter every time how often do you change the oil? i go 10k and the lose filter happens around 9500 miles

Wow sounds like your truck is learning.......it doesn't want the fluid changed at 10K it wants it done at 9500...:lol:

I tighten mine (use AC Delco or Wix) as tight as I can get it by hand with a piece of 320 grit sandpaper surrounding the filter for extra grip. I haven't had one come loose yet and they still easily remove with a filter wrench.

Tighten the filter one full revolution after the rubber seal touch's the housing you will never have a problem!