To keep this Thread going, here is the inside track, insider information, and a treat for you......
This may go against the "Trend" and fly in the face of few that have had problems, but I am not a bad Mechanic and Engineer and this is also my synopsis of owning and following about 125 Fords with our Bushtracker Owners:
1) The 7.3 both IDI and the PSD were great engines, dirty, crude, noisy, but great solid engines and were only stopped because of EPA Emission Controls... Both my IDI and PSD went strong, never had a real problem, and carried on for the next Owners..
2) Again, maybe fly in the face, but the 6.0 was also a good engine baring a couple of points: The Emission Controls were weak, up on their maximums with the EGR coolers in particular; and the head bolts and gaskets were not up to taking high performance tunes. You could rectify both, and when you did, the 6.0 was a solid performer. I owned 2 of them, 06 and 07 King Ranch F-350 Duallies... The EGR coolers were a weak design, over heat and over pressure with a tune and they had problems and some had problems with running stock. My impression is that 95% of all problems with the 6.0 was caused by running higher horsepower tunes by the Owners... This however, because people would not admit to it, this gave Navistar a black eye for what was basically a pretty fair engine.
3) Now I have only limited experience and study, and only 13,000 kms on my 09 F-450, but with my Contatcts I have an inside man from the Australian Import and Service Company, and one in Texas at a Dealer. My conclusion from the studies of the Engineering and the records on 85 trucks in Australia and a few hundred in Texas is that Navistar went OVERBOARD on building the 6.4 PSD to save its reputation. It was NOT an interim engine as some call it. From the redesign of the EGR Coolers, to larger head bolts, to bed plate to support the lower end, to improved head gasket designs, we have a GREAT engine from the old "International Harvester" Company... Here were (are) the discovered flaws:
A few job one trucks had an oil cooler problem, faulty castings that came apart, Ford came good on that one... Have not actually seen any of those, so this is second hand.. The sensors in the exhaust are finicky (get the back one and carry it as a spare, read the code and swap it out, clear the code.) The only other major weakness is the new high pressure fuel system is fragile if you get bad fuel and water gets to it. (Got news for ya, ALL brands/models have the same problem with the new ULSD high pressure systems and it is a $12,000 repair on Cummins, $7000 repair on the V-8 Landcruiser, $10,000 repair on the Duramax, and exotics like BMW and rest can be more expensive yet.) Run a water separator filter addtion to your stock filters. I run my diesel into a 240 litre tank and pump out from there through a water separator filter with a clear bowl to watch for water and pump into my main tank. A perfect design would be a Racor or Dahl clear bowl water separator filter before the Ford ones but I have not done it (Yet). Drain your lower filter out a few ounces once a month and look for water in the bottom of the sample in a cut clear coke plastic bottle type of thing... Run clean diesel, and you eliminate 90% of the potential problems.
We have a GREAT engine. It is possible that Fords 6.7 is going to be good, but International Harvester "Navistar" now, in my opinion built us a great engine. It will be years before we know if the Mexican built 6.7 is going to hold up with consistency and quality control..
This is my .02, but it is worth a heck of lot more than that, as I do this R&D Professionally on behalf of my Clients at Bushtracker... I also have spent over $150,000 A$ about $130,000 U.S. $ on a new F-450 King Ranch with the right hand conversion, new dash, new steering and all the rest; and added Air Brakes over the hydraulics, air suspension over, and upgraded the GVM to 7500 kg. You do not spend that kind of money lightly...
Anyway, there is my Professional report and opinion. I may stick with my 09 F-450 as the new ones have gone to smaller diff, smaller wheels, smaller brakes, and just upgraded an F-350 with the Fugliest fenders on dually since the 1950s... :hehe: My King Ranch 4x4, has 19.5 wheels and heavy steel in commercial truck tyres, bigger brakes, 10 stud wheels, and a Dana 110 diff that looks like it came out of a Semi...:hehe::nod: I may dig in right here and make a stand.
Please update this Post with high miles reports. Lone Ranger in Oz....