Cadillac Repair: Coolant loss, oreilly auto parts, wire coathanger

Question
I have a 1998 Cadillac Deville with a Northstar 4.6L engine. I had a leaking heater core, which I had replaced.  However, I still am incurring coolant loss.  The floor boards in the passenger front compartment, (both sides) are wet. Initially, the wetness was only on the passenger's side.  I have since had the water pump, water pump belt tensioner, and belt replaced.  Normally we will do our own work, if we can locate the problem.  Any advice would be greatly appreciated!  

Answer
Hi Alicia,

      If the wetness is due to a coolant leak there are only 2 ways it can get into the car...the replacement core was bad or damaged durring the installation or the hose clamps were loose allowing coolant to leak past and into the car if the seal at the "firewall" was bad. Is it possable that the heater core/evaporator core drain is plugged and it is really water that is soaking the floor? You should be able to see the drain elbow after raiseing the car up and looking under the evap. core houseing at the "firewall". Use a wire coathanger or 14ga. house electrical wire to see if by pokeing into the hole that an obstruction is opened up.

    What you might need to do is get a coolant pressure testor, remove the rad. cap and install the testor there and pump it up to look for the leak source. Since you already know how to remove the cover to access the heater core you would be able to tell if it is leaking and where. They can be bought at bigger auto parts stores or might be part of a loaner tool at places like AutoZone or OReilly auto parts. A few phone calls to parts stores in your area and you'll know for sure. Otherwise have a shop pressure test it and see where the leak is and then you can replace the parts.

     Hope that helps. Bill