I can't believe im asking this, but i've never seen it before and I can't figure it out. This is on a 2001 2wd 24v cummins.

When I check the engine oil level theres a gap in the oil right at the add mark. Then the oil continues up to the full mark. I don't know where the oil level is????

When I changed the oil 2 weeks ago I had 3 gallons, but only put in about 2.5 then checked the dipstick and it looked how it is now, I was confused but left it.

Anyone notice this or had this problem? I've worked on alot of cars and trucks and I've yet to see this. So thats why I'm asking. thanks for any help

edit: this is the engine oil level

 

added more oil, its reading normal now...it did that for 2 weeks and now it stops the day I post this...