Hey guys. I've managed to replace a faulty piston and installed a complete new set with rings. I replaced the tensioner and 1 valve. Now the car runs well but as soon as it gets hot and the oil gets thinner it makes a knocking noise between 3000rpm and 3500rpm. It almost sounds like one of the tappets. When I did the pistons I stripped the head and took all the tappets out and assembled it again but in no particular order. I want to know if there is a particular way to install the tappet ( lifters) or maybe where the fault may be. Any help will really be great...