The 6.4L had poorly lubricated valve rockers which were known the fail. The turbocharger plumbing on the exhaust side also failed fairly regularly at the back of the motor and was hard to get at. But I agree, most of the problems were due to the emissions control system.

 

Agreed.
The whole installation package was a cluster.. in more ways than one. Just a joke to service.
But the 6.4L engine itself, in a non EGR condition was a completely different animal than the pathetic stock configuration. I fully understand the overwhelming opinion and disappointment with the end product from Ford.
It’s a damn shame that 99.99% of the 6.4L owners had NO idea what they really had under the hood, and with a little research, what they could have had at the time..

I never had a single issue in the 8 years of 345 added horses. It was also personally serviced every 3k with full synthetic. Overkill I know, but the results were zero issues, and a towing monster that would still be the king of the hill today.

 

I owned a 6.4. It was abysmal and quickly justified the purchase of a 6.7. Navistar and Ford cut way too many corners on that engine and when it failed, regardless of the cause, the failure was incredibly expensive to recover from.

Yes, the engine had plenty of fuel and air to make big power, but that's about the only thing it had going for it. Driving around with a deleted truck just isn't an option for me so any perceived benefit there was by driving an illegal truck was just a pipe dream.

The Ford 6.7 is a joy to own in comparison. No, its not as easy to modify to make crazy power like a 6.4, but that's just not what most people are looking for in a truck.

 

In my opinion, Ford also missed the ball in properly training their techs on the 6.0. There was a massive learning curve on this engine and it took app. 2 years for most of the techs to get up to speed. A lot of repairs were done 2 and 3 times before the root cause of failure was figured out. This gave a basically sound engine a bad reputation.

 

There is no blame on the 6.4L design. The basic engine design from Navistar was perfect for its time..

The problem with the 6.4 was the same shared problem That afflicted every 2008-2010 Cummins ISX and the Caterpillar C-15 over the road engines. And that was the 100% EGR treatment emissions equipment sattled on it from the manufacturer. Caterpillar exited the class 8 market after the same warranty issues as Ford.
The almost 40% pure hot exhaust into the intake was just an oil killer and intake choker.

If the 6.4L was equipped with today’s CSR emissions technology, it would have been a different story.

Today, the new 6.7L drives so un-diesel like, it’s almost too good to be true. Instant response, tons of stock power.. I can’t wait for 2020 and the 10 speed.

 

Clearly the 6.4's problems resulted from the addition of the emissions equipment, which wasn't used on the higher weight class commercial truck applications.

Ford had a target for the HP/TQ numbers, with EGR, to be competitive in the market. My assumption is International turned the tune up and assumed it would be OK.

Sadly, Ford would have been better off with a modestly revised 6.0 than the 6.4.

 

international wasnt the ones that turned the tune up.. it was ford.. they did it with the 6.4 and 6.0 which caused problems.. then tried t blame international for the problems despite being warned not to do what ford wanted to do..

 

International could have said no. Or said; if you do we are not responsible. But that would have been a deal breaker. Responsibility is shared. International designed the engine and, as I said, Ford had target HP/TQ numbers for it. International knew what those numbers were, did the deal anyway.

 

As I understand it, both ford and international were caught with there pants down when the levle of the duramax performance info first came to light. They were already in the development cycle and realized they were going to produce a non competitive engine in the next year so ford rewrote the rules of the game and pushed for more HP. Additionally, International requested release on MY2004 so they had adaquate time to test drivability and reliability. Duramax trucks were flying out the doors and Ford pushed international to release the truck midyear 2003 in order to capture some of those buyers before they spent their money elsewhere. In ford’s view each sale lost resulted in a 3-5 year delay of potential customer

 

I've owned multiple 6.0, 6.4 and 6.7 trucks (still do -- have four) and my recommendation -- find a Cummins or a Duramax/Allison.

 

This guy is not buying ford because 6.7 is made in Mexico on a previous thread, now he's recommending buying trucks made in Mexico.

 

 

Yep. Saw that too.

 

First..
There is “in” cylinder treatment technology of the past (EGR), and the present “after” cylinder treatment (SCR/DEF)

The 6.4 issues had nothing to do with Ford. It had nothing to do with Navistar. As I posted above, everything from the 08-10’ model year engines suffered from the only archaic emissions technology available at the time to meet Tier 3 standards of 2008. EGR..

Once MY 2011 was introduced with the new SCR/DEF after treatment technology from Europe, EGR was able to be cut back by 40% to meet emissions.. As SCR technology was perfected in the last couple years, EGR was turned down further along with turning up the amount of DEF after treatment. This allows tuning to be done with an actual fresh air charge, instead of a cylinder full of oxygen killing, oil polluting exhaust gas from EGR.
Simply said, Emission standards are now met by treating the Nox “after” the fuel charge and power stroke instead of during the fuel charge and power stroke.

 

January 1st of 2003 saw a significant reduction in allowable NOX emissions in new trucks being produced. The mighty 7.3 could not meet these new emission standards. The 6.0 was delayed as long as possible, resulting in later 2003 trucks to get the 6.0 if i recall correctly.
Who dragged their feet in development i do not know.....