I get a tap-tap-tap noise from my engine. It is not very loud but is starting to bother me. I took it down to the local diesel shop and they couldn't figure it out. They definately say they can hear something and did a valve lash inspection and visual on the valves and couldn't find anything. They finally sent me home and told me not to worry about it, but now I am worried about it. It seems to be louder at some rpm levels than others and sometimes it seems to go away. I can coast down the road in neutral and still get the noise as long as I keep the same rpm's. Could it be injectors and possibly be fixed by getting new ones or is it most likely a valve problem? Thanks, Tom J.

 

sounds more like injector noise from either timing, or pressure. The 600 engines will "sound" like a tap-tap, or a faint rattle, I have the noise on mine, but it goes away when the smarty is set for no timing or returned too stock. I think it has something too do with the 3 injection events, but that is a guess.

Jon.

 

This may sound kind of stupid but have you checked to make sure that all of the inector line hold downs are tight? I have seen one of my own vibate loose and it drove me nuts with the tappig noise that i made. Just a suggestion.

 

I will have to take off the valve cover for this right? Do you know how tight these should be?