Exhaust leak or stuck lifter?

Exhaust leak or stuck lifter?  When I started my 2000 Chevy blazer ZR2  (111000 miles) the other night when leaving work it sounded like it had an exhaust leak. After the engine warmed up the noise went away. Since then every time I start my blazer (when the moter is cold) the same problem occurs.  Could an exhaust leak do this or would it be a lifter or something else.  There seems to be no loss of power.  Any suggestions?  Any additives or something that I can add to fix if it’s a stuck lifter?   Thanks for any help. 

I would say that you should be able to use a mechanics stethoscope to pinpoint the location of the noise.  If it's coming from the valve cover it's a lifter not pumping up properly.  If you find it down at the exhaust manifold, then you've got an exhaust leak.

Buy a can or two of SeaFoam to hopefully free up a sticky lifter.