So after I found that my valve cover was loose and I lost a little oil, I pulled out my dipstick to check oil level. I cleaned it off, and looked and looked, but I can not find any oil level indicators! I searched, but came up with nothing. My tranny fluid level dipstick has 3 holes in it, but my oil dipstick has nothing. Did the dipsticks somehow get swapped before I bought the truck? How do I know if I'm running low on oil?