Hi I am new to this forum I created my account today I’m sure there are plenty of posts on this subject but I have little clue how to operate this website. As well as I’m new to idis. I bought a 1984 6.9 idi that was sitting for 8 years due to brake failure and the owner having a stroke. I bought it changed the starter fluids and filters plus glow plugs after that it cranked right up and ran like a top no excessive smoke or anything but there was a knocking sound it was more of a ping not a rod knock. It’s very loud if you’re laying under the transmission moderately loud if you’re standing by the drivers side door and can barely be heard if your head is in the engine bay. Did research it could be an injector knock. Loosened lines and found out when I loosened injector number 8 the ping/knock disappeared entirely replaced that injector the sound was barely there even laying under the transmission but within a few minutes it got louder. Any ideas? Thanks in advance