1. Knocking noise from EJ20 Engine. The engine has a difficulty from the 4th cylinder. This cylinder is best; the cooling is even worse With this put of the engine. In this instance, the piston or rod begins knocking then the engine is cold initially and all time right after https://titusoilew.blogerus.com/51965616/detailed-notes-on-jdm-subaru-ej20-engine