So... My passenger floor is wet after driving all day. I am assuming this is due to the heater core about to fail? Is the heater core easy to do? Thanks!

 

First question is whether it's actually antifreeze. There's a pretty characteristic sweet smell if the heater core is leaking.

Otherwise what about rainwater leaking from the cowling area around the air intakes, or wiring harness passthroughs?
Is it warm enough for the air conditioner to run? Enough humidity to condense in the AC evaporator and maybe the drain hose is disconnected?

 

It is antifreeze. It smells musty sweet. I imagine there are countless online tutorials I can reach out to. Seems like the heater core is relatively inexpensive. Hopefully it's not as difficult to replace as it was on my Jeep Grand Cherokee.

 

I think you have to pull the dash out to get to it.

 

I'd recommend getting a shop manual for your car. automanualsource.com has a pdf you can download for ~$20.

I'm pretty sure you will have to remove the heater unit to replace the heater core. I'm also pretty sure you will have to remove the dash.

 

Got the shop manual, replaced the thermostat, and did a drain and fill on the coolant. So far, I haven't had any more wet passenger floor. I'm sure the core is about to go, but for now, I'll hold off. Thank you all for your input.