N14 Ticking sound

04 peterbilt 379, 525 n14

I have a ticking noise that sounds like it is coming from the top end at the rear of the engince. I have searched till I cant search anymore on the internet and seem to run into the same diagnosis that it is an air leak, injector, or needs a valve adjustment. I have had it in the shop twice now and have had two valve adjustments and the injectors checked, o rings replaced, and adjusted and still have the problem. I have sprayed gallons of soap and water on the engine as well as replaced all of the clamps and flexpipe around the turbo and downpipe. I can hear it from idle to 1500 rpm driving or in neutral. When i go above 1500 it seems to go away but that is at about 73mph. The sound does not seem to change much with weight differences. Same loaded as bobtailing.

I have no excessive blowby and my oil pressure is normal. I have also had an oil sample done and it showed all ok as well.

As of now I have ran it 30k miles like this and doesn't seem to get worse or better.

Anybody have any other Ideas? Could it be cam wear?
Also does anyone have any suggestions for mechanics or shops that are very familiar with n14 engines around oklahoma city? I realize they all work on them and the shop I have had it at twice now is very reputable. I trust them and have used them for years now but im going crazy having to listen to this thing all the time.
Any help is appreciated

 

That is what it sounds like but you can put a screwdriver up to the valve cover at the rear of the engine and seems like its coming from right there at the jake/valve cover area. Definitely not a leak there because gaskets have been replaced twice now. Im almost certain its something in the top end. They cannot find anything that is out of place or worn at all. No rub marks, nothing.

 

thanks for the replys. It does sound like it could be in the jakes. They were adjusted and seem to work better but still make the sound. I think i will find a cummins deal rather than trying to take it to rush or something like that.

 

yes that is what I am most concerned about. It doesnt sound normal at all.