6.7 reliability

97cherokee

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so id take a 6.7 any day over a 6.4, with that being said about 2 years ago i wanted something newer with the bells and whistles, power and more comfort than my 7.3, jumped into a very nice and well maintained 2014 lariat ultimate with right at 201k. at 220k i got bad fuel, wiped out the cp4, did a disaster kit, fuel cooler and fuel module at 4200 in parts... then i got worried about the turbo a few miles later and did a 15 retrofit kit. had a few more issues over the next few weeks and decided too sell it and go back to my old 7.3 that is cheap and easy too work on with the plans too do a few more engine upgrades and interior upgrades. it definitely wont be as fast or efficient as the 6.7, but i worried less about working on my 380k 7.3 than i did my 228k 6.7.... just my 2 cents.
 

sootie

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so id take a 6.7 any day over a 6.4, with that being said about 2 years ago i wanted something newer with the bells and whistles, power and more comfort than my 7.3, jumped into a very nice and well maintained 2014 lariat ultimate with right at 201k. at 220k i got bad fuel, wiped out the cp4, did a disaster kit, fuel cooler and fuel module at 4200 in parts... then i got worried about the turbo a few miles later and did a 15 retrofit kit. had a few more issues over the next few weeks and decided too sell it and go back to my old 7.3 that is cheap and easy too work on with the plans too do a few more engine upgrades and interior upgrades. it definitely wont be as fast or efficient as the 6.7, but i worried less about working on my 380k 7.3 than i did my 228k 6.7.... just my 2 cents.

what a stupid time to sell the truck...just after you eliminated all the weaknesses!
 

sootie

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So rhe 6.7 takes several thousand to make it reliable?
Is that the norm or an exception?

Incorrect. The poster got bad fuel, which wiped out his high pressure system. His proactive turbo replacement may or may not have been necessary.

Job 1 6.7s had the following common issues:

-trucks built prior to April 2011 had a heat treat issue with the exhaust valves, which would cause them to come apart and wipe out the motor.

-Transmission valve bodies had some funky activity regarding low speed, low throttle percentage shifting. Ford issued a TSB for this, and the solution was valve body replacement.

-2011 model year trucks had plastic oil pans which were leak prone. 2012 + came with steel and they are a direct bolt on replacement.

-11/12 turbos had turbo bearing issues due to the inherent design, and that is why the 13/14 turbos were a slight improvement, and a hard boost limiter installed on the PCM. Most problems showed up in tuned scenarios. 2015+ turbos are a direct bolt in swap and have been exceptionally reliable and support just under 600hp

Some 6.7 notes:
-I have had multiple job 1 6.7's, some of which dropped valves, some of which did not. All well over 200k miles.

-I had a job 1 6.7 with a modded 2015 turbo, stroker hpfp and stock everything else last over five years and 50k of abuse, on stock everything including trans. Dyno'd 668 / 1248. I sold it and its still ticking in the same form.

-13+ trucks had my ford touch with the updated dash and centre console. Also platinum trim became available.

-Cold side intercooler pipes had a habit of splitting under high heat/boost/load scenarios. Host of cheap aftermarket options available. Updated on the 17+ models.

-Rads often leak at the seam as they are a plastic end tank. Most commonly because of failing cab mounts or high suspension articulation circumstances. Don't be tempted by the solid aftermarket options- they fail even sooner as they dont allow for flex.

-Clean fuel is of utmost importance if you want the fuel system to survive.

Conclusion:

11s are hit and miss but mostly hit. 12s are prteey solid but move to 13/14 for advanced tech and turbo reliability. 15/16 are the last of the "real steel" super duties and have been tremendously reliable. 17-19 are decent but had some body issue growing pains (leaking windows / roofs, poor panel adjustment, wiring gremlins), but still had the 6 sp trans. 20+ have subtle engine changes and the 10 sp trans which i HATE.
 
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lincolnlocker

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I put 133k on a 2012 that got drove very hard without issue after weight loss at 40k with zero issues. I bought my 15 at 109k and have 186k on it now. Freak issue with some injector failures on one bank but other than that, no issues and it gets the snot drove out of it daily...

Dont 6.4s crack pistons as well?


Its not "if" a 6.4 is going to fail, its "when"...


Edit, i forgot that the pcm went bad as well at the time the injectors went out. It was said that the pcm going bad took out one bank of injectors according to ford tech line.
live life full throttle
 
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powerlifter405

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Thanks for some insight.
On the 6.4s that failed, I ponder if a duh leet with stock fueling would create a viable truck?
Engine failures seem to be oil related, ie extended oil drain or idle time and i can see that contributing to fuel becoming a dilutent. Idk, just guessing but it makes sense as a contributing factor.

@Sootie thanks for the run down on ur trucks.

On the fuel issues, aside from a "catastrophe kit" what filtration improvements can be made to keep the hpfp from dying. In 20 years of owning diesels never had gelling, even in -42 Minnesota until this winter.
Been using the same fuel station for the last 2 years, as do some farmers etc. Its a heavy use station but it was -6 windchill here in Kneebraska and I had gelling. Added some 911 and it started up but those things can happen.

How would I save a 6.7 fuel system? Could I do some class 8 filtration and separator after the fuel conditioner?
 
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DEEZUZ

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It's not just filtration. It's air. Air is really what causes the HP pump failures.

Unfortunately I really can't stand behind many of the aftermarket fuel pumps cause all I see is problems with them but I do know the factory fuel pump does produces alot of air as well.
 

DEEZUZ

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Anything is possible with fittings. Lmao.

But even those pumps provide a little bit of cavitation
 

powerlifter405

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Hahaha no sh+t man LOL. I mean would added filtration be a legit benefit?

So how do you solve cavitation then? Or can you?
 

DEEZUZ

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I'd say the filtration is adequate. Water separation could use some work I think. But one should be draining it monthly anyway.

I only install Fass systems and they seem to have the air under control when I plumbed in clear tubing.

My other shop sware by Air dog...

I see failures across the board
 

sootie

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A 6.0 or 7.3 hfcm doesn't produce enough pressure to keep the 6.7 happy, you need 80-120 psi

Adding a glass bowl type water separator wouldn't hurt for sure.

And no, a stock fuel, deeleeted six four is still a time bomb. No telling when a k16 will give up or a lifter will lunch the cam. Pistons have a real knack for cracking out of the blue also.
 

powerlifter405

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I'd say the filtration is adequate. Water separation could use some work I think. But one should be draining it monthly anyway.

I only install Fass systems and they seem to have the air under control when I plumbed in clear tubing.

My other shop sware by Air dog...

I see failures across the board

How reliable are the Fass and Air Dog? Years ago I remember reading about them randomly dying leaving folks stranded.
Whats the failure rate for a 6.7 w/o it and stock fueling, any ideas/thoughts?

A 6.0 or 7.3 hfcm doesn't produce enough pressure to keep the 6.7 happy, you need 80-120 psi

Adding a glass bowl type water separator wouldn't hurt for sure.

And no, a stock fuel, deeleeted six four is still a time bomb. No telling when a k16 will give up or a lifter will lunch the cam. Pistons have a real knack for cracking out of the blue also.

Ok, for some reason I was thinking the 7.3 was higher.

Yeah, I figured maybe get a multi head and add a 5 or 2 mic filter and another water separator. Cheap insurance.

Well at the current cost of 6.4's I'll probably flush that idea. At one point I considered a 6.4 and then when it goes to the 12v swap for funnsies. But at $27 or higher thats not practical. I found a few 6.7's w/ 150k miles + or - that are in the low 30 range.

My other option is going gasser. I found some NIB F150 w/ less than 45 miles in the $34 range, 3.5 EB w/ the 10spd, locker etc. IDK, food for thought I guess.
 

powerlifter405

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Why must you poo on my party LOL

I've towed 4 maybe 5 times in the last 7 years so you can understand why I've considered downsizing. My aunt has a 2017 5.0 with the 10spd and gets about 23mog at 75mph empty. She's got a 25ft and at tow speed she still gets around 14mpg.

Is 18-19mpg hand calculated realistic at 75mph empty with the 6.7? I retire in about 4 years so I'll need to be more conscious about fuel expenses.
 

lincolnlocker

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Why must you poo on my party LOL

I've towed 4 maybe 5 times in the last 7 years so you can understand why I've considered downsizing. My aunt has a 2017 5.0 with the 10spd and gets about 23mog at 75mph empty. She's got a 25ft and at tow speed she still gets around 14mpg.

Is 18-19mpg hand calculated realistic at 75mph empty with the 6.7? I retire in about 4 years so I'll need to be more conscious about fuel expenses.

Well, i guess you wont get that good with a 6.7... ever. Lol.. my 12 did. That thing was insane. I could get 17mpg with the cruise set at 90 but not anything after that year..

55 mph i can get almost 20mpg with my 15.. but 16ish mpg at 75-80 mph 14ish mpg at 90mph.. hook my brothers gooseneck to it with 20 round bales of hay and it gets 8ish mpg..

live life full throttle
 

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