That must have been quite a sight with your tongue on the piston. Did you taste, er, I mean feel the other pistons as well for a comparison? It would suck to pull the pan only to find out that you were imagining things.
I already discussed pulling the pan in a previous post. Once the pan is off, remove the rod cap and push the piston out. You should see/and or feel the problem soon enough. Do all 4 while you're at it.