1999 jeep wrangler leaking coolant from short tube coming out of the firewall below heater lines

heater core may have a leak.

Sure. Just could be a loose line

It appears that you have a blown headgasket, a failing water pump, or a cracked block.

There is also the possibility of a freeze plug failing & leaking there.

You can bypass the heater core until you are sure your engine problems are corrected so as not to damage it from excessive pressure.

You'll need to reassemble everything and pressure test the system instead of starting the engine, to see where the leaks are.

Good luck !

heater core and evaporator drain tube under the dash stopped up. go underneath the vechicle firewall under hood area. go around heater cores coolant hoses some where below that area you should have a drain tube opening, take a shop vac tape small hoses like vacuum line 3/8 inside diameter vacuum out debris in ac drain tube that should help inside leak problem.

freeze plug or intake. Most auto parts stores sells a red dye you can add to the coolant. Then you need a ultra violet lamp to see where the leak is. The dye will show with the UV lamp with a bright glow

located on passenger side below heater box toward the bottom of the firewall. going to be about a 1/2 tube sticking out about 1 to 2 inches.

Not really, there is a tube and I be it is connected it just gets clogged...... let me know what year Jeep it is or you can look on the passenger side firewall and you will see a tube that points down the is it . try squeezing it then you can pull it out it is real easy to put back in.. Clear it and drain the A/C..

If you look on the engine side of the firewall on the passenger side about even with the bottom of the heater box, you will find a short pliable stub hose. you can clear it by rolling it between your fingers or using something soft and inserting it into the hose (using anything hard or long can damage stuff inside the box) Once cleared, you should have no more problems.

I have a 1993 Jeep Wrangler YJ...My heater core needed replacement when I bought it about a year ago. I made the mistake of taking apart the dash to get to the heater core. DO NOT DO THIS!!! It is actually 4 screws that you must take out from the inside of the engine compartment on the firewall. Then it will come right out. Have fun!!!

Clean the drain plug by the Battery under the hood, It's clogged.