4.0l OEM oil filter check valve?

My truck has been sitting for 5 days. I am changing the oil and when I took off the filter nothing came out, I thought there was a check valve? Maybe not.

Yes, I am changing the oil cold.

 

There should be an anti drain valve... They don't always work and sitting for that long it is most likely going to drain back.

You should also run the engine a bit before draining anyway as it suspends the solids that settle while sitting and results in a cleaner engine drain.