What could be causing a coolant leak from the back of engine?

What is your question?

I appear to have a coolant (has the smell of radiator coolant) leak but not from radiator itself or the hoses going to it; the leak seems to be coming from the bottom of the back of the engine; it appears to be leaking on or around the skid plate. What may be causing this and is it easily repairable or is it an indication of a major engine issue? Besides smoking from apparently I think hitting the exhaust pipe going into the back of the engine after about five minutes of running, there does not appear to be any other engine issue like loss of power or even the temperature gauge reflecting a higher temp than normal. Thanks for your help. Scott

What makes this problem better or worse?

Running for over five minutes

How long has your 1994 Nissan Pathfinder had this problem?

First noticed last week and have not used car since that time