Air leaking with r coolant at bleeder screw on driver's side when opened

What is your question?

The van overheats. The temp pegs the needle and will cause the motor to stop. Let it sit for 25 minutes, and you can drive it another 5 miles if lucky. Sometimes temp needle will go to the left side of the red zone, stay there maybe 5 seconds and head back down to where it belongs. What can be the problem? There are no apparent leaks, except the overflow will have a little less water. The bleeder on the passenger side only has coolant coming out.

How long has your 2003 Chevrolet Venture had this problem?

several months