Nissan Repair: coolant loss, losing coolant, coolant loss

Question
QUESTION: My 1993 Nissan Altima 2.4L just started losing coolant. I'm not sure if it losing while running, however when the car is shut off fluid runs out of what appears to be a drain hose underneath the riderside firewall. Interestingly when the A/C is turned off, it doesn't appear to leak. The temp remain  normal and the AC runs very well. Thanks for help in the past hopefully as well as this latest development.

ANSWER: Kameron,

The heater core or the heater hose feeding the core is leaking.  At a given temperature, like when the airconditioner pushes the temperature up the car leaks.  I would check the hoses first and if that is not the issue you are looking at the heater core.  Check the drain to see if that is where the coolant is coming from.

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QUESTION: Thanks again for your help. It is definitely coolant. I live in S FL and never use heat. Is it possible to bypass the entire heater core issue  by connecting the in going  and outcoming hoses. I've read in the repair manual that this job is not for the home mechanic (ME).This vehicle has 258,000.burns no oil,good umph etc.

ANSWER: Kameron,

Yes, you can loop the hose between the two lines coming from the engine as a stop gap measure.  The heater core can wait until you get around to it.

---------- FOLLOW-UP ----------

QUESTION: This is getting more perplexing. I bypased the heater core. Still noticed more fluid come from drain tube on the heater core box after driving for awhile with ac running. Today it began to run the temp gauge way towards hot. Can there be any other hoses in that dead space between the firewall and heatercore recetacle?

Answer
Kameron,

The heater core should just be leaking what is left.  Second, make sure the looped hose is not kinked and will allow water to loop back.  Want proper flow here.  If you have the airconditioner on the system will drip condensate from the evaporator being cold.  That is the real reason for the drain tube in the first place.  Check to make sure your cooling fan is coming on when the air is turned on.