Before anyone says it: yes I know.
But.
I parked the D1 in the garage around ten days ago and haven't started the motor since. The floor has the carpets out and was dry when I parked it, and the coolant reservoir had coolant in it.

Now, the reservoir is empty and the floor has puddles on both sides at the outer edge of the truck.

I had thought leaky heater cores only flooded your floor with the help of the water pump, but is it possible for it to passively dump coolant in my footwells with the truck just sitting for a week and a half?

On the bright side, the coolant isn't exiting via the head gaskets..

 

Yes it's possible and with a rover highly probable.

"Land Rover finding new and creative ways to leak fluids since 1947"

 

Time for a diaper change....... trucks getting old don't cha know. Don't count your eggs before the chickens lay - you might still get a head gasket leak once you seal up the system, that's how it works, always keeps you guessing - "Where did that coolant go?" Coolant senility, early onset.

 

Thankyou for the replies. Will have to do a bypass of the heater until I can gather enthusiasm for replacing the core.
If it's not one thing, it's something else...

 

You know, it could be worse, could be a P38.......

 

or classic

 

Bypass will also remove the built in diagnostic of hearing bubbles from leaky head gasket rush thru the heater core. Other posts are correct to indicate this is the start of more fun. The truck is built around the heater core.

 

The heater core was pretty quick to access (after pulling the dash....)

On my truck, there was a leak into the cabin, but it was actually coming from the heater hoses where they attach at the firewall. Couldn't hurt to make sure those are tightened properly

 

That is definitely something I will check before taking anything apart! thanks.