My heater core is leaking in passenger side floor board and you can smell it when I turn heater on. Do I have to pull dash to replace it? 2000 Dodge Ram 1500 Quad Cab 5.9 Lt, 4x2

Does the water smell like coolant? Are you losing any coolant from your radiator/reservoir? If so, you have a heater core leaking. It's a large job to replace, requiring removal of the dash.
If it doesn't smell like coolant, it may be that the drain tube from your a/c evaporator is plugged, and condensation is leaking into the passenger compartment. Look for the drain tube on the engine side of the firewall, in front of the passenger and down low. It should be a rubber tube that has nothing connected to it.
Other possibilities are leaking sealant around the windshield, bad weatherstripping around the doors, and leaks from sunroof (if you have one).

Are you able to see if it is the heater core? Located in dash on passenger side. Can often see them from bottom of the dash if you stick your head down by the floor boards.

Hello,
If you can smell a little bit of a sweet smell from the water on the passenger side floor, or if it has an oily film to it, you may have a leaking heater core.

They usually leak on the passenger side floor, and that might explain why you hear water sloshing around.

If you can run the engine for about 5 minutes and then turn your heater on. Look under the dash in the area where the dash meets the floor board and see if you can see anything leaking.

I hope this helps you.

That would be a bad heater core. You will see water leaking from the passengers side floor board. This is a complicated job to do as a do it yourself being the heater core is located behind the dash.

1st make sure it's the heater core. Usually it's the passenger side that is wet. To confirm it's the heater core, 1. do you smell antifreeze? It has a sweet smell, and should be easy to notice it if leaking. 2. Do have a problem with the windows fogging up, and turning on the defroster doesn't help or makes it worse? If the core is leaking, the moisture from the leak will fog up the windows, and the defrost mode struggles to clear the glass, as moisture is blown up the vents onto the glass. If 1 and 2 don't exist, the water on the drivers side is most likely a leak from rain along the door gasket, or windshield, or firewall.

check the seals on the doors, also check heater core coil which is under the dash, if your smelling a sweet smell it could be antifreeze leaking out of the heater core

Hi Big,

Heater core is on the passenger side under the dash.

Are your coolant levels low?

Start your engine and set the heater on high. This allows circulation through the core. Now check for leaks. Place a paper towel or two on the floor. This will allow you to see the color of whatever is leaking. (e.g. antifreeze)

Fogging will only occur when there is a temperature differential of more than one or two degrees between the inside and outside of the vehicle.

Best regards,
Mike

there is air in system causing gurgling/set heater to defrost and check for sweet smell. do while stopped if core is leaking windshield will fog up and be hard to clear.

Your definitley on the right track,it maybe the actual heater as most heater hoses end at the firewall so the leak must be on the inside of the firewall. If you cant spot the leak from the engine bay side you may have to remove the dash, hope this helps.

Your heater core is leaking. It is inside of the heater box. disassembly is required