rlchv70

No offense, but I believe some of these values are low. EGRTA should be able to go up to 1380F before derate.

I believe it is 245F.

Could also be exhaust gaskets.

The HP fuel pump can suck fuel from the tank, but it's not designed to. It will quickly fail due to cavitation damage.

Picture looks eroded. If it's not eroded: Any possibility the truck was chipped?

Is the F-450 radiator the same as the F-350s?

You can see erosion of the bowl at the ~8o-clock position. However, the photo gets cut off at 12 o-clock. What's it look like there? If it is eroded there, then, I would guess that the crack actually initiated there.

Vertical marking is common and considered normal on both the 6.0 and 6.4L Also, do NOT use a dingle ball hone on any modern engine. Hone specifications have come a long way and are very precisely controlled at the factory.

One hole is oval to prevent the chance of binding. Orientation doesn't matter. Pushrods were shortened to correct a manufacturing tolerance build up issue.

I think you have it backwards. Likely, the piston cracked first, then melted the piston.

My understanding is that it is a combination of cavitation, and erosion/corrosion. Any particles in the system will help to erode it. Have you done a good flush? Any leaks in the system will exacerbate the condition. Does it hold pressure? How's the pressure cap?

My opinion is that it would probably be okay. The gasket has less tension on it during a combustion event than it would by loosening 1 bolt at a time. However, I would just quote him 2 prices. One for studs only and one with studs and gaskets. Show him that it won't be much more to go ahead and replace the gaskets and you have better peace of mind.

The horizontal cooler is under more stress, it is more likely to fail. I have only rarely seen the vertical cooler fail. I've had some success with using EXTREMELY hot, scalding water when they don't leak with warm water. Of course, take precautions with this. Using dye to detect a leaking cooler is an interesting method. Might be worth a shot next time.

It is possible that the coolers will only leak when hot.

The 6.4L EGR strategy does not use the MAF sensor. It uses the EBP sensor and MAP sensor to determine EGR flow rate.

Actually, I think it would. In order to understand if the DPF needs a regen, the ECU looks at the exhaust backpressure. However, this is a function of the amount of exhaust flow. The exhaust flow is proportional to MAF. A simplification is that it will regen when it reaches certain MAF/backpressure combinations. If your MAF sensor is reading high, it will think it is flowing more air than it actually is. Therefore, with a higher flow rate at the same exhaust pressure, it will lead to more frequent regens.

From my understanding, the ECU used the DPF pressure sensor in conjunction with the MAF sensor to determine how much soot load there is in the DPF. It actually estimates the amount of soot in the DPF.

Have access to a bore scope?

The way I would do it is to pressurize the cooling system and bore-scope each cylinder while under pressure. Use a flexible scope so that you can look back up at the injectors and glow plugs. Cracked heads or crankcase are also possibilities, but rarely seen. Have you pressurized the system to see how long it holds? You mentioned that you let it cool down overnight after a hot run. Did it leak then? Could this just be normal degassing after a coolant drain and fill?

Other possibilities: injector and glow plug sleeves.

Usually see that when HP pump goes out, sending debris to the injectors.

I've seen them both ways. It's possible that the cylinder can flll and prevent the engine from turning over without bending or breaking something.

Did you test the EGR cooler on the subject truck? Is it possible it hydrolocked to prevent it from starting? After sitting overnight, the cylinder could have drained to allow it to start.

May also be the injector harness or an intermittent connection between the harness and the injector(s).

Your Wikipedia link links to the wrong site. Here is the right one: Wikipedia - Compacted Graphite Iron