Join Date: Dec 2009
Thanked 36 Times in 32 Posts
If you keep up with proper maintenance, do not "mod" the truck and it wasn't abused prior, you aren't likely to have problems.
My boilerplate maintenance recommendations:
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 10,000 miles at the same time you do the fuel filters 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.
* 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 Deisel-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 does not provide continuous indication of when a DPF regen is taking place. 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.
Keep up these maintenance items and you should have few issues unless the truck was abused prior to your purchase. 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.