Diagnostic Help Needed

[Striper Mike]

2003 6.0 F350
Recently started make a single "chew" or multiple "chew chew chew" noise when running at 2000 to 2500 rpm's at high way speeds. Noticable momentary loss of power, hesitation or bucking going up inclines such as over passes. When you think will happen, it doesn't, and when you think it won't, it does...very random.

Anyone have any thoughts.

[Evil Eye]

What is your Injector Control Pressure (ICP) and Injector Pressure Regulator (IPR) duty cycle when it has the loss of power? We need some diagnostic information in order to offer up suggestions.

[Striper Mike]

I'm a rookie at this whole diesel thing. How do I find out what the duty cycle is for the ICP? Evrything on the truck is stock other than putting on a Banks Ram Air Inlet Sytem to facilitate filter replacement.

[Striper Mike]

Note: It did this before I put on the Ram Air. No difference. The first couple of times it did this I the frequency almost most made it seem like road imperections that I was traveling on.

[Evil Eye]

You will need a diagnostic tool (not just a code reader). I use AutoEnginuity, although there are other tools out there that can be used.

[Striper Mike]

Some additional info. I was pulling my 20ft fishing boat (3700 lbs). Only did it at highway speeds. No issues off the line or hard pull at lower rpms. Friend of mine says it sounds like waste gate flutter as on large diesels. While on the trip he did some searching and thought that maybe EGR valve may need cleaning or replaced. EGR seemed to be a very common problem that could give these symtoms. Your thoughts EvilEye

[Evil Eye]

Yep, the EGR valve could need cleaning and it is a common occurrence to get all coked up, although it wouldn't give you those symptoms. Do you have a check engine light or any codes?

[Striper Mike]

No, no lights or error codes.

[Evil Eye]

Yeah, you definitely need to find someone who can run some diagnostics for you. Where are you located?

[Striper Mike]

Indianapolis, IN