Most of the hits I get from smoking my pipe don't have much smoke from it.. when I exhale no smoke comes out but I definitely know smoke is going through the chamber. Joints, blunts, bongs, and other people's pipes give me a lot of smoke but it seems to be my pipe not giving me much.
you probably have resin stuck in it that isn't plunging it, but reducing the amount of smoke that can get through. that or if its like old and beaten up or somethin you might be getting air from somewhere (but thats really unlikely)
Some pipes just dont produce thick smoke, most of the time the fault lies in a mishapen bowl. Could it be the way you pack it?
Cheap pipes tend to not produce much smoke. If its a quality piece its likely that it's defective. Probably an air leak