I have a leak in the back of the engine. looks like a pipe coming from the firewall on the passenger side, about halfway down into the engine. is this a freeze plug or a heating issue?

Hi Mr.Downs.
Are you sure is only leaking when the vehicle gets warm? On checking the coolant level when the engine is cold and before starting is in a correct level?
Is it possible to be any drain pipe either if you do have air conditioning and running the air con then water comes out from that pipe and might you do have any dirt by the vaporator and gets the orange color.
Also do check for your power steering fluid,if there is any leakage
from the steering rack if it is close to that pipe and confusing you ?

It sure sounds like the heater core, especially if you have water leaking inside the cabin. The two heater hoses only go from the engine to the firewall, and do not go into or through the firewall. They connect to the heater core right at the firewall.
Check carefully around the back side of the engine and the heater hoses, though. If a freeze plug is leaking, water will be dripping off the bottom of the engine. If it is leaking before the firewall, that would not be the heater core.

It sounds like you're looking at the heater core water lines. These connect to the heater core supply and return inlet and outlet pipes to bring hot coolant into the cabin for heat and windshield deicing.

The heater core is a mini radiator and operates on the exact same principles as the radiator does. The heater core is located behind the dash board on the passenger side. Look for a wet spot of antifreeze on the passenger side floor area - close to the firewall for an indication of a leaky heater core. If it is leaking, it will likely need to be replaced. This can be a pricey repair.

Good luck!

Leaking inside sounds like the heater core. If the core is broke right where the heater hoses connect, it might be losing coolant down both sides of firewall, inside and outside. Otherwise, look for a leak at the intake manifold. That might run down back of engine near the transmission, as you indicated.
Good luck.

Check the heater control valve and the hoses where they go into the firewall. If the leak is not there, then the most likely problem is a leaking heater core. You need to look carefully to find the source of the leak before you can repair it. Use a flashlight, mirror or whatever is necessary to do that. If it is a hose, use extreme care removing it from the heater core connection. best to cut it off with a razor blade. If it is the heater core,most times it will make the passenger side rug wet. If it is the core, it isn't an easy job and I'd consider either getting a haynes or chilton manual to guide you, or, have a good shop do the work.
good luck

drill a hole through the floor as a quick fix ,if it gets in let it out ,then check for the leak ,try under the firewall where the AC drain pipe is ,it could be the same pipe for drain water coming in from air intake vents

In the dashboard,set down low is a driptray.It collects water that comes off the aircon.It has a hose (sometimes 2) that drains the water out of the car via the firewall so it drips onto the road.This is blocked or the tray has a buildup of gunk.The hose is about 1/2 inch thick.If you lay on the floor where it leaks with a torch you should find it.Or look in the engine bay,just to the left or right of centre(which side leaks?)and backtrace it into the car.You may find the inside hose has fallen off allowing the water to drip inside.Hope this helps you

Just had ours fixed, look on engine side of firewall, if the outlet pipe in passenger well is a 3/4 inch long pipe projecting forward into engine bay with no tubing leading down towards the ground, the problem is water comes out trickles back with pressure in engine bay to foam seal under the pipe and enters footwell inside car.
Take a piece of rubber tubing and hose clamp it on and direct it down towards ground in engine bay and the problem will be solved!
We have gone from soaking carpet to no leak at all with this simple fix.
Rgds Martin

Air conditioning drain stopped up with debris (leaves,pine straw,sticks). Small tube sticking out from firewall with rubber elbow pointing down behind engine, passenger side. If elbow missing air will cause water to back up into vehicle. Another possibility, if your coolant is low heater core leaking.

A/C drain pipe blocked with old leaves and dead flies the outlet is on the passenger side of vehicle lift bonnet and look a lower of firewall for a rubber pipe with a **** in the end and squeeze it and shake it