I have an injector thats knocking, I had one a few months back that went south and it did tick but this one is really loud. Its not leaking into the oil because i drained the oil and the level was fine and it didnt smell like diesel. Could it be stuck or what? I can really feel it hammering when i touch the # 1 injector line. I dont think there is anything i can do to it unless i pull it out and clean or replace it. Any help would be greatly appreciated!