My carpet is wet at various times on the passenger side UNDER THE MAT. I figure this is my heater core, although i dont know much about this particular part of the truck. What Blows my mind is have made a routine to figure out the source of the water/moisture. I is only under the floor mat, the carpet is wet, but when i pull the carpet up, the floor pan is dry and not rusted. I run my hands all up around the dashboard and anywhere i can guess i leaks from. I need to find a way to trace this water b/c I think there is a possibility it may be coming from some loose body bolt from my body lift and water is entering. SO.... if the heater core is bad and or leaking ... should water ever collect on top of the mat? Or maybe should it run down the carpet from an exact location. Whoa..What an long and boring topic..I just hope someone has some input on this b/c i would hate my floor pan to rust.

 

Hmm...well, I can tell you this much. When the heater core went on my previous truck (A Chevy), it was very obvious that the heater core was at fault. There was coolant on my passenger side floor and that distinct smell. If all you're getting is water with no sign and/or scent of coolant, I doubt that your heater core is the problem. Honestly, it sounds like you may just have a piece of bad weather stripping that is letting water leak into your truck. I'd look into that first, maybe pour some water down from the top of your windshield and then take a close look at where the water was previously inside the truck. Good luck, hopefully it isn't the heater core!

 

Been running your a/c lately? that could be your source...find where the tube comes out of the firewall on the passenger side and give it a good flik with your finger and see if water doesnt start coming out of it,,,flik it a few more times to make sure it clears