rlchv70

Jim - you are correct. FYI, the International rocker arms are different PNs and are a little more robust to this issue.

Same until the 2010 Maxx7.

I believe that this is a NOx absorber. The issue with it is expense of the catalyst and additional fuel consumption since you have to regen it like a DPF. Also, it only works well on light load factor usage. The Dodge Ram 2500 and 3500 pickups use this technology. More info: http://en.wikipedia.org/wiki/NOx_Absorber

Yes and no. Greatly simplified, it is true. However, the details are more complicated. First, Urea is not ammonia. It is (NH2)2CO. It has to be heated by the exhaust gasses to break down into ammonia. The reactions are more complicated than shown and require the SCR catalyst to occur. More info: http://en.wikipedia.org/wiki/Selective_catalytic_reduction

FYI, the DEF is not used only during a regen. The regen is for the DPF, not the SCR catalyst. The DEF is continuously injected above a certain temperature.

FYI, warranty rates on the 6.4L are better than the 7.3L ever was.

It's either check for metal or have the truck come back later for injectors...

I agree with your assessment except for the last part. The HPFP likely went first, causing the injector leaks.

Use the gaskets, use new bolts, and make sure the manifolds are flat.

Check for fuel in the secondary cooling system. It is possible the fuel cooler is leaking. Fuel system doesn't like coolant.

Anyone notice the tow vehicle in the pic where the "Excursion" is on a trailer?

I've seen it before, not sure of cause, though.

Yep. But now that Indy is shut down, they may be doing it differently.

It was a change made a couple of years ago. My understanding is that it was implemented to address a tolerance stack up issue. The lifters should have plenty of margin to accommodate it. I doubt it was the issue with lockup. I would check for stuck valves or a miss-timed camshaft.

The crankshaft is machined with the flange installed. They don't want you to remove it due to the issues you state. However, International dealers are allowed to change it. This version includes a secondary geartrain that drives the power steering pump and a mechanical LP fuel pump. They want to be able to change it in the event of geartrain failure. If you are very careful swapping it, use new bolts, properly torque it, and check runout afterwards, it can be done. Bit of trivia: the crankshafts are machined with the Ford flange installed. The International flange is then swapped in its place when designated for that application.

For the record, you might be able to do it in-chassis, but I don't recommend it. You'll either have to remove the rear crank flange (not recommended) or find a way to drop the bedplate and crankshaft. On a 6.0L, I don't think there's a way to do this without removing the heads since the head bolts hold the rockers in place. On a 6.4L, you can remove the rockers and pushrods, flip the engine over, spin it a couple of times so the lifters get pushed up into the guides, and then pull the cam.

Were the springs and keepers in place? I've seen the valve tip break off at the keeper groove. Other possibility would be a stuck open valve. Do the other valves move freely in the guides?

Don't rule out the EGR coolers...

They are relying on passive regeneration. To passively regenerate, you need high exhaust temps and NOx. With the 6.7L, since it has SCR, the engine out NOx is likely higher than on the 6.4L. Therefore, it will passively regenerate more easily. With the retrofits, pre-2007 engines also have higher NOx outputs. This allows them to passively regenerate more easily. Some of the systems require a certain duty cycle to ensure that they passively regenerate. Also, some of the retrofit kits allow some of the soot to pass through, unlike the 2007+ OEM equipment. Here's more info on the equipment available for retrofit. As you can see, some of them actually include systems for active regeneration: http://www.epa.gov/otaq/retrofit/verif-list.htm http://www.epa.gov/otaq/schoolbus/retrofit.htm

More likely, it's the turbo drain.

Running with broken t-stats may exacerbate the pitting on the front cover. With aluminum, some amount of pitting is considered normal.

It's likely coming from the injectors. You could narrow down one bank by disconnecting and plugging each cylinder head. Otherwise, no other suggestions. Just checking: You remembered to put new combustion gaskets on the injectors, right?

Above a certain GVW, emissions certification has to be done via engine dynamometer since it is considered a "heavy duty" application. Below that GVW, OEMs have the choice of certifying it as "light duty", which is done via chassis dynamometer. The EPA cycles for the light duty vs heavy duty are very different. The light duty spends more time at lighter loads. That way, The OEMs can calibrate for high power and torque numbers without worrying so much about emissions.

You are correct. If the t-stat is "hyperextended", then the "main" t-stat does not function properly.

Any previous repairs on the truck? Had a very mysterious tick on one 6.4. Finally decided to pull the head and found the intake and exhaust valves switched. Other things that I've seen on 6.4s are gear damage and lifter damage. Ford and Nav were chasing a ticking noise that seemed to be associated with crankshafts and/or bearings. I never heard of a final root cause on that one, tho.