Test Drive, Need some expert advise please...
Yesterday, I test drove an '04 F350 CC Dually with the 6.0 PowerStroke, automatic and a 4.10 rear end. About 75,000 miles. I really like the truck, as it is in immaculate condition, has been carefully maintained and has about as close to my optimal option list as you can get. Still... The reputation of the early 6.0 engines has me very nervous (this was a 7/29/03 build). My primary use for the truck will be towing my 7,000# travel trailer. We live in the West, so mountains and heat are the norm, and I don't want to leave my family stranded in the middle of nowhere.
Anyway, the truck seemed to drive very nice until I really jumped on the throttle. The current owner has installed a gauge cluster with a boost gauge (oddly though, he chose a clock instead of a pyro gauge to go with it). When you really stand on it, the boost shoots right up to 25-30PSI, but then you would get a chuf-chuf-chuf (with attendant puffs of smoke out the exhaust), and the boost would drop to about 15-20PSI in 5 PSI increments. Power drop off was very noticeable as well. You could get right back on it, and the boost would go right back up, but about 80% of the time would do the same thing.
My first thought (I have no practical diesel experience) was that it was an over boost pressure pop-off valve doing it's job, but if that was the case I wouldn't think it would let the boost go that high to start with. I had a friend with me that knows a lot more about diesels than I (But not Fords, he is a Dodge guy), and he thinks it is more of a miss and may be indicative of serious issues.
So my questions to all you 6.0 experts, is this a normal condition (i.e. pop-off). If not, have any of you seen a similar symptom, and have ideas about what it might be? Also, is 25-30PSI a lot of boost for this engine, or is that normal? I don't believe the truck has been chipped.
Also, about the 4.10 rear end. That seems awfully low to me for a diesel. Is that a pretty typical spec for a dually maybe? And between that gearing and dual rears, any thoughts on what kind of fuel mileage I might expect?
I did get an OASIS report, and it is clear that the truck has been carefully maintained, but a few issues did show up:
At about 11,600 miles it had an issue with dying while driving at 30-40MPH on the flats. The report shows a lot of diagnostic work, but I don't really see a fix in it.
At about 36,500 miles the 'Check Engine' light would occasionally come on, and would die on turns to the right, then run very rough for 5-10 minutes. It looks like they did EGR and EBP sensor work, and found the EBP sensor (not sure what that is) stuck due to carbon buildup. Appears to have been rectified.
Two months later at 39,700 miles there were more 'Check Engine' light troubles. Performed VGT solenoid (again ???) warranty work, "Found VGT off at AT". Again, appears fixed.
Another two months later (11/05) at 41,500 miles, owner reported "Water in fuel" light coming on. Lots of diagnostics, but I don't see anything fixed. The problem was not reported again, so I'm not sure what to make of this?
Finally, in 12/07, there was an issue with a lack of power on acceleration. Found turbo 'Y' pipe leaking and fixed it. At the same time, found and fixed leaking rear main seal and CAC hose. Also, performed a control module re-flash (looks like a recall issue).
Do any of these issues maybe shed light on what might be happening now? Also, are these issues that suggest that I should run away from this vehicle as fast as I can?
I apologize for all the questions, but as I said, I am nervous about the 6.0 reputation to start with, and this whole oil burning world is new to me. I do thank you for your time to read all this. I truely appreciate any advise or help I can get on this.