hey I'm new here...but I was reading about the bad smells thinking it was going to be the moldy evaporator coil but come to find out they are very clean no mold or mildew anywhere reading further I saw where they talked about a clogged drain line so I got under to check it when I stuck my small screwdriver in to see if it were clogged which it wasn't but when I removed screwdriver it had antifreeze on it & after smelling it that is the exact smell coming from rear vents. But I can't see antifreeze anywhere like its a leaking pipe or anything. Help me out. Thanks

 

2005 Chevy Tahoe z71

 

Leaking heater core.