shriek above 1000 rpm. noob to diesels
Hey guys, I am new to diesels. I know how they run but have never worked on any specific engines. I just bought an 08 6.4 250SD 4wd and it has a shriek. it doesnt seem to effect performance but i have no idea where to start troubleshooting.
It has 108,000m and ~5300 hrs and used to be a service truck. I dont see any soot on the firewall, and the noise sounds like its coming from the drivers side lower engine bay, which in my research points to an up pipe. It starts at about 1000 rpm and continues to get louder and increase in pitch above that, unless I have it floored then it gets quiet but I can still faintly hear it. It still makes 30-35lbs of boost according to the dash.
The dealer I bought it from sent it to the shop for the same shriek but a different tone and rpm band, he said the shop told them it was an exhaust gasket because a bolt broke (of which I am kind of skeptical).
A diesel mech friend said it sounded like it could be an injector, but again I am unfamiliar and it still makes power.
I dont have money for a tuner and exhaust and egr delete right now otherwise I would do those and hope it corrects the issue lol.( They will be done in the near future)
Any help is appreciated