I have a sick 600 with a BAD engine knock and took it to the local dealer. Well, the dealer found two bad injectors; they say one had worked its way loose. Anyhow, they replaced the bad injectors and the knock is still there and it seems more noticeable now. I must admit, the service manager is doing all he can to make sure it gets fixed. He did a dealer trade just to get new 05 in so he could do a side by side engine idle comparison. Well, they spend all day Friday and the better part of the day today on the phone with STAR doing "tests" to see what is wrong. His next step is to send it to the local CUMMINS dealer to have them fix it. At least they are working with me. Here is my question to all the pros out there. What do you guys think the loud knock could be, has anyone had this sort of issue? I need my truck back for a trip down to Kentucky tomorrow night. Any help form you guys that I could pass along to get this thing fixed would be awesome. Thanks in advance.

 

Perhaps you lost pilot injection? However this would tend to sound simply louder, more like an older series 24-valve sound, not specifically a knock. Could have a real problem down in there? Document everything and be prepared to take it to a corporate level if they give you no soultions.

 

sounds to me like if the injector worked it's way loose, the piston may have started to melt due to incorrect injection timing. deffinately would cause a fuel knock. the problem i have with your situation is that dodge has to fix that truck, a cummins dealer can not touch it under warranty. just the rules of the game