'04 f250 misfire, and more
Hey guys new powerstroke owner, and before everyone jumps me, yes I did search. Alot. And found alot of people having similar issues but nothing exactly like mine.
Anywho it's an 04 f250, 183k miles on it and it is bone stock. Bought it real cheap needing "motor work" and I was happy it had no rust anywhere and has almost no body damage. I must say it is a previous flood truck at some point in its life. I don't think it was in that deep of water being there's no visible water damage anywhere (father in law works for a rebuilder and even he couldn't find a water line)
The truck runs and drives, it had a misfire tho. A friend of mine works on 6ohs so I have him do the work on it for me. It comes up with cylinder 8 imbalance. Changed the injector out with a new ford one he had at work, and it didn't change. Still missing #8. He changed the oil (I never thought of checking it) and pulls out 22 quarts of thinner than 15w40 oil but it did NOT have water in it. It definetly runs better but still misses. New batteries, changed out ficm and ecu and it pulled the valve cover and watched the valves move, they all function as they should and return to the same height (like not bent valve train). It does build some pressure in the cooling system, but a huge amount. All 8 injectors buzz the same when you do a buzz test, and when you shut each cylinder down in the scan tool 7 of them make it shake like crazy when shut off and when you turn #8 off it BARELY makes a difference in rpm. I thought a piston could be broken but there is no blow by out of the breather.
Oh, and it cranks over fast. Like, very fast. It's a smooth fast not a choppy one cylinder easier fast. But it's alot faster than any other 6oh I have heard. So I start it, it misses. Put it in gear and throttle it to move and it shudders until about 2500rpm and it smoothes out. It smokes gray like a train, and the turbo surges like crazy. When it gets a hard load on it it surges reaaally bad and the engine bucks with the surges. Now, at idle, I have the intake off (open turbo) and it makes a funny noise out of the turbo, I assumed because it is missing a cylinder it's not getting fed steady. Use the scan tool and open the vgt all the way, it goes away.
Sorry it's a book. I can't take videos, the intake is off for the egr delete I got for it. I was leaning toward needing a head gasket. I'm just baffled at changing so much and getting no change. I thought low compression on #8 but it doesn't have blow by and only a small increase in coolant pressure. I am lost guys :/ any help is GREATLY APPRECIATED!!