Water dripping from mufler

I store my 2003 Silverado 1/2 ton over the winter.  I drive it
occasionally when the roads are dry, maybe putting on 500 miles in 4
months.  Once in awhile I back it out of the garage to get it out of
the way then let it idle a few minutes to let the oil and coolant
circulate and battery charge up.  The last couple of times, I’ve seen
water dripping from the bottom seam of the mufler.  And it’s left a
trail of water back into the garage when I’ve put it back in.  I
assume this is water coming from the converter.  The sound from the
exhaust hasn’t changed and I don’t see exhaust coming out of the
mufler.  The trucks got 50,000 miles on a 5.3 l engine and with the
original exhaust system.  Is the mufler shot?

-- 
Posted at author's request, using moderated http://www.AutoBoardz.com
interface
Thread archive:
http://www.AutoBoardz.com/Water-dripping-mufler-ftopict247300.html