I'm looking to buy a 6.4L for heavy towing and know they had some issues but was looking for a thread or sticky on what to look for to avoid problems. The only things I know of now is that I have heard they can get terrible mileage until they are deleted/tuned. I also heard with a tune they get really powerful. I have heard they had much less head gasket issues like the 6.0L but they can have EGR issues too. The ones I am looking at have over 140K and are F350 or 450 with flatbed that I will use with gooseneck to tow a car hauler not a daily driver. I have some experience with the 6.0L and those issues but found a good shop that was able to correct all its issues so I will stick with that shop for next truck. I wanted to learn as much as I need to avoid getting a money pit.
Thanks

 

The 6.0's and 6.4's in my opinion are good trucks if you delete them, head studs for the 6.0, and don't get too crazy with aggressive tunes.

 

The 6.4 will be no less money pit than a 6.0 IMO. Everyone who I know that had one couldn't wait to get rid of them at some point. If I had to choose, I would go 6.0, but in reality, I would have neither anymore.

Sig- 2014 3.5EB 2"level 285/70/17 3.55. Most recent trucks: 6.7stroke, 6.7cummins, 5.4f1, 3-6.0'strokes, 5.9CRcummins, 9-7.3's, 4.6f1stick, LB7, 12v5.9, VE12v, 350v10...

 

A pickup with 6.4 is fairly hard to work on compared to one with a 6.0 only because of packaging in pickup itself. If you have access to a two post hoist to lift cab then it makes life a lot easier when the time comes.

I bought a 2008 about 3 months ago with 122,000 miles and absolutely love it! I had an alternator failure one month in and when it gets below zero the radiator leaks but other than that no problems. Other than difficulty of working on engine and lifting cab I don't think these are any more or less money pits than GM and Dodge diesel offerings. Most failures tend to be related to government mandated emissions crap and people driving a lot around town not working them. From what I researched they all have various problems, forums like this with people looking for help and major parts such as turbo, injectors, transmission, anything related to the word Diesel engine are all expensive to replace, especially if you have to pay a dealer to do work.

I finished my delete last month and have seen a 2mpg increase in town up to now 15 and a 4mpg change on highway to 20. I have no power increase chip, only shuts off emissions stuff.

For what it's worth I love mine and wouldn't hesitate doing it again.

Jeff

 

That is the opposite story of everyone I know with a 6.4...

 

For heavy towing, I would recommend DPF / EGR deletes, offroad tuning to disable regens, but leave power at stock, or just slightly over.
Buying a used truck with a few miles on it, carries it's own risk.
A 6.4 truck with 100,000 could be in mint shape, or ready to die, depending on the previous owner.
See if you can get the hours off the cluster, so you know engine hours along with mileage.
Favour a 6.4 with lower hours than higher.
A 6.4 used for heavy towing with 100,000 on it is likely in much sounder shape mechanically than a soccer mom 6.4 truck with the same mileage.

Once you get the emission junk off, IMHO, they are just as reliable as any other common rail diesel you can buy today, which is in it's own way, a downgrade on reliability compared to older injection systems, but what are you gonna do.

 

I for one am quite happy with my 6.4, indeed I am particularly happy to have a truck that is now going on 6 years old and 115k that I still love.

The key to 6.4 happieness is maintenance - **** retentive maintenance. I bought my truck new (2009 F350 6.4 KR CC DRW 4x4) and since then have done oil changes every 5k with Mobil1 5W40TD and Motorcraft filters and Blackstone oused oil analysis, and fuel filter changes every 10k again with OEM filters. I have also done the coolant nitrite testing regularly and added VC-8 when needed, and coolant flush and replacement at 60k per spec.

My current maintenance recomendations that have been serving me well:

The 6.4 does not typically "self destruct", in many cases it is aided in destructing by operator who do not understand the requirements of the new emissions controlled diesels and use them for the wrong type of service, neglect maintenance, etc. Properly operated and maintained the 6.4 and other emissions controlled diesels do just fine.

Now if you are looking at a used one, you have to be concerned about it's useage and maintenance prior to your purchase. Unlike pre-emissions diesels the post-emissions diesels can go bad very quickly if they are neglected or are used for all short trips.

The problem with assessing a used post-emissions diesel is that much of what you want to inspect is not readily visible. On the 6.4 you would ideally want to inspect the following:

- Lower HFCM fuel filter and housing for signs of gunk buildup, and to ensure the filters have been changed.

- Upper fuel filter, looking in the bottom of the housing for signs of rust spots or metal flakes both of which can mean expensive fuel system repairs.

- The water pump back housing for signs of cavitation damage.

- Coolant nitrite test to see if the coolant has been maintained properly.

- Used oil analysis on a sample with ~5k miles on it.

- Check for signs of leaks at the radiator hose connections and the radiator itself.

Since a used vehicle at a dealer has probably recieved a basic service with new oil and filters, some of the information you want will not be available at all.
Clearly the water pump housing can not be inspected in any reasonable fashion. The lower HFCM filter and housing can't be inspected without draining a quart plus of fuel and making a mess so it's not easily inspected.
The upper fuel filter can be inspected fairly easily with a flashlight, wrench and a container to rest the filter in when removed. This is one inspection you should absolutely do since a high pressure fuel pump and injectors is a good $8k repair.
The coolant nitrite test is another quick and easy test you can do, clip a test strip on the end of a long hemostat and just dunk it in the coolant degas tank, wait the 45 seconds and compare the color chart. Most dealers probably won't change the coolant on a used truck so it your nitrite test shows under 300ppm nitrite, reject the truck for neglected maintenance.

My standard maintenance recommendations for the 6.4:

If you have not owned one of the newer emissions controlled diesels previously (any brand), be aware that they are far more dependent on proper maintenance than earlier diesels.

Key 6.4 maintenance items:

* Oil changes every 5,000 miles, with quality oil (synthetic recommended), used oil analysis (Blackstone) for every change. Use only Motorcraft oil filters or the Racor (OEM) equivalent.

* Fuel filter changes every 10,000 miles. Use only Motorcraft FD4617 or the Racor (OEM) equivalent filters.

* Coolant nitrite testing at least every 15,000 miles. I recommend every 5,000 miles at the same time you do the oil change for simplicity, the test strips are inexpensive. Do not be confused by the test directions warning not to sample from an overflow tank, the 6.4 does not have an overflow tank it has a degas bottle. The degas bottle is part of the coolant loop with constant circulation so it is a valid testing point. I do not bother "taking a sample", I simply clip the test strip on the end of a long hemostat and dunk it in the degas bottle to test. If the test is below 800ppm and above 300ppm add two bottles of VC-8 additive. If below 300ppm the entire coolant system must be flushed with VC-9 cleaner, rinsed well and refilled with new coolant.

* Cooling system flush with VC-9 and refill with Ford Gold coolant every 60,000 miles, sooner if you have neglected testing and the nitrite is under 300ppm.

* Use a quality fuel conditioner such as the Ford PM-22a/23a conditioners at every fueling. They add lubricity to the fuel, something that ULSD is lacking in which helps protect the high pressure (up to 26,000 PSI) fuel pump. They also help to reduce soot production which results in less frequent DPF regens and less fuel dilution in the engine oil.

* Drain the HFCM water separator monthly. The fuel drained can be poured back into the tank carefully leaving behind any water at the bottom of the collection jar (normally very little). If the water separator drain does not flow well or at all, it may be clogged with either parafin blobs or with bacterial growth. In either case at a minimum the drain valve cover needs to be removed and the clog cleared. If the clog is significant the HFCM cover needs to be removed for full cleaning. If the clog is white and waxy it's parafin and not a significant issue. If the clog is brown or similar and more slimy it is bacterial growth and the fuel tank should be "shocked" with a biocide such as Power Service Bio-Kleen which should not be confused with their Diesel-Kleen.

* The truck should not be used for all short trips and stop and go traffic. The 6.4 and other emissions controlled diesels need regular longer periods at highway speeds to allow proper DPF regeneration and to get to proper operating temperature to help reduce fuel contamination in the engine oil.

* The latest PCM flash (11B23) does not provide continuous indication of when a DPF regen is taking place, it does however add much improved engine monitoring for developing issues. Over time you will get to recognize the subtle changes, but I recommend adding something like the ScanGauge II which will allow you to monitor the DPF temperature which is a clear indication that a regen is in progress when over ~600F.

* Avoid shutting the truck down with a regen in progress. If you have to, run the engine at high idle for a few minutes in park before shutting down to allow the turbos to cool down to normal temperatures before shutdown. If you are interrupting the regens you will see it in your Blackstone report, otherwise you should see very little fuel dilution, <1%.

You should also absolutely get the Ford ESP extended warranty, any repairs to the 6.4 are expensive and a single big repair can easily cover the cost of the ESP warranty. The coolant nitrite testing that many people overlook *is* in the owner's manual diesel supplement, so if you neglect it Ford can deny warranty coverage for resulting damage.

Other Super Duty maintenance items:

* Batteries - The batteries in these trucks are not the maintanence free / unmaintainable type, pop the caps to check and top up with distilled water periodically.

* Change transfer case fluid every 60,000 miles.

* Change rear differential fluid every 50,000 miles on DANA axles (F350 DRW and up).

* Change transmission fluid and filter every 60,000 miles on Torqshift transmissions (100k on manual transmissions). If you have the early Torqshift with the external filter the interval is much shorter.

Resources:

Coolant test strips - Buy the 4pk, not the bottle of 50, the strips have expiration dates and you'll only need <10 per year. Most dealer parts counters should have the test strips, NAPA has them, or order direct from Acustrip.
Ford Rotunda 328-2050
Ford Rotunda CTS-3 3-Way HD Antifreeze


The Ford Rotunda 328-2050 (CTS-3) series of test strips provides a fast and simple manner for testing SCA and freeze point in antifreeze coolant. Test your coolant frequently to protect against liner pitting, corrosion and coolant dilution. This three-way test strip measures Glycol, Molybdate and Nitrite. The Specific ranges are as follows:
Nitrite 0 - 3200 ppm
Molybdate 0 - 1000 ppm
Glycol 0 - 60%


Used oil testing - Blackstone Labs, get the pre-paid 6pk of test kits to save a few bucks. You don't need the TBN option:
Blackstone Labs

Ford ESP extended warrantys - You can buy them online from real dealers, or use the online price from a real dealer to negotiate a better price from your local dealer. You absolutely want the ESP, while the 6.4 is not problematic as some claim as long as you maintain it properly, nearly any repair is big $ and one good one will cover the ESP cost:
Ford Extended Warranty | Genuine Ford ESP | Discounted Pricing

DPF, oil, coolant temp monitoring - ScangaugeII, you will need to program the X-gauge commands for the 6.4:
ScanGauge - Trip Computer + Digitial Gauges + ScanTools
Ford/Lincoln/Mercury Specific : Linear Logic : Home of the ScanGauge

 

WOW a lot of very useful info. A few questions.

What causes the cavitation old or improper coolant or something else?

I know EGR deletes on 6.0L can be electronic (tune), block off plates or new new piping what are the preferred options on the 6.4L

How is the DPF deleted?

I looked on Ebay and the injectors are 2300-2500 new Siemens which they say are the OEM manufacturers and the HPFP are 900-1200 new why do I hear 8k-10k fuel system replacement cost. What parts or services am I missing?

Is ELC a good option for coolant? I have read that Ford Gold can cause problems in the 6.0L from the heat generated in the coolers plus the sand from castings if it is not changed religiously at intervals.

Is it true the auto trans is a stronger version of the one behind the 6.0L's or is it the same?

 

The 6.0 and the 6.4 both use the 5R110 transmission. I don't know if the 6.4 has a stronger version over the 6.0.

 

6 years and 115k with Blackstone reports on every oil change while 100% stock and legal has convinced me that removing emissions equipment does not actually solve any problems and may only mask them.

 

True words of a person that has never owned a tuned 6.4, glad yours has been trouble free, I find it hard to wonder what a delete would mask but no need to go into details, one day if we ever have the chance to meet I'll let you take my everyday grocery getter for a drive, but I warn you it will probably change your mind.

 

Wanted to rep ya Bubba, but gotta spread it around more...

 

I think the main reason people do the delete and tune is that you will get rid of components that can cause problems, and to get better mileage. The added HP is just a nice plus added to that process!

 

The reason common rail fuel systems can cost 10k$ like people say, is that if certain parts fail, the whole system becomes contaminated.
At that point, if you just replace say the injectors, the contaminated fuel can just destroy the new injectors.
If the fuel system becomes contaminated, the only proper answer is to replace almost everything.
If you only replace the injectors, you could face replacing the injectors, then replacing everything again later, when it fails again.
This is not only a 6.4 problem, or ford problem, it is a common rail problem.

With an older mechanical pump unit injector system, or heui like the 7.3 and 6.0, if fuel got contaminated, the injector would foul, and you would get a sputter or miss, or the injection spray pattern would be off, and wouldn't burn quite right.

With common rail, debris in the fuel system can cause an injector to fail, but the failure mode, since the fuel rail is always at injection pressure, is for the injector to hang open, and eventually melt down a cylinder, if it doesn't fill the crank case with fuel first, and ingest that and hydro lock.

Common rail performance unfortunately brings this negative side effect with it to any common rail engine.
If the high pressure fuel pump craps the bed, the entire system must be replaced.
You can try replacing part after part, to fix it, but that could really bite you in the ****, if you and up doing a complete replacement anyways.

Think of it like a wet basement with a mould problem, you might see mould on 1 wall, and want to rip just the one wall apart, but chances are there is mould all over the place, and you'll end up ripping apart the entire basement to fix the mould problems.

 

Ditto! The 6.4 is way more reliable.