I have just put new pistons in my civic ex 93' d16z6 and theres a knock sound coming from the motor i though it could be rods not torqued down so i pulled motor apart and torqed then put back together and still knocks i know its not the rods wrist pins or main cap bearings any other ideas??? knock gets noticable around 2000rpms any help please ????

 

another indacation that might help is that when i put the new pistons and rods in and put them on the crank and finished the bottom end i was going to put the head on and the two middle pistons 2 and 3 are at the bottom and 1 and 4 are at the top when its in time and i was reaching down into cyclinder 2 to clean some debris off the top from cleaning the old head gasket i notice that if i push down on piston 2 and 3 at the same time they would make a pop sound and move down just a little bit not much but like the width of a piston ring for instiance. the sound they make is like when first putting the pistons in the motor and tapping them down to the crank and when they connect to the crank that the same sound i here when the motor is running???? and i have check the rods they are torqued crazy any help plzz someone