The Mighty Furd Gets a Report Card
The Mighty Furd’s lab test report is in and, on the whole, it’s quite good! Blackstone Labs is located in Indiana, so sending in a sample from Arizona via the Post Office takes a week, plus a couple of days to do the test and write up the results in humanspeak. They are one of several outfits that can test any automotive fluid you send them, and the usual goal in doing so is to evaluate wear status as well as fluid condition. In this case, if my oil’s additives are pretty well used up, then it’s high time for an oil change no matter what the odometer says. If there’s some coolant in the oil (or vice-versa) then it’s likely high time to address a blown head gasket. If trace metals commonly found in cylinder walls, the valve train or elsewhere are found in unusually high amounts, then decisions can be made now instead of during a mechanical crisis.
Since knowledge is power, then the the whole goal here is to become aware of budding problems long before they can wreak their havoc on your wallet. The more of your resources you have tied up in your vehicle(s), the more dependent you are on them for income, or the less financially able you are to deal with major breakdowns in equipment, the more valuable it becomes to know ahead of time what situation is or is not coming up. While it’s normally much cheaper to suffer the costs of regular maintenance than the costs of neglect, it’s also typically much cheaper to catch and address individual problems as they surface, than it is to wait until the damage has been done. Sitting beside the road with a connecting rod sticking out of a hole in the crankcase is a bigger problem to deal with than having to shorten up your oil change intervals. With the 6.4, not all potential harbingers of doom throw a visible warning flag ahead of time, but enough do that it pays to monitor what one can.
Having engine fluids analyzed – in my case engine oil – is not cheap. The base rate at Blackstone Labs runs $28, and for that you get a sheet of numbers that compares your engine to previous tests on it (when applicable), as well as the average values they have found for your engine group. For an extra $10, they test for your oil’s remaining additives, which can be useful if you are trying to decide whether to do oil changes on the standard interval or the short “Severe Service” interval described in your owner’s manual. At an oil & filter change cost of over $100 at retail for my diesel, changing more often than necessary is a literal waste of money, while waiting too long to change will shorten the engine’s service life. Blackstone offers a “bulk” purchase of tests for a base of $25 each, available in whatever quantity you want. I purchased six tests with the intent of eventually working out just what my oil change intervals should be for my particular usage, as well as hopefully getting a head’s-up on upcoming problems. In essence, you’re buying credits with a bulk purchase, and each sample you send in is deducted from that standing total. There is no time limit to use them up.
Consider for a moment my paranoia surrounding the 6.4L Navistar-supplied diesel engine that Ford used from 2008-2010. Are these just the ravings of a madman? Well yes, of course they are. You’ve read this blog before. It’s what I do. Other than a cracked radiator tank (a common 6.4 problem), my particular Super Duty has posed no engine-related problems since new, running with all the finicky fickleness of a refrigerator. It doesn’t like poor quality fuel as can be found in northern Missouri, does not like a steady diet of urban-style errand stop & go, and can’t use more than 5% biodiesel without the risk of damaging its expensive emissions system. But actual engine problems needing attention? No.
My paranoia is based on the documented behavior of the 6.4 in the wild. On average, the Navistar 6.4 has been a stout and capable performer with an unusual degree of complexity to help it handle heavy use without violating the stringent new emissions standards of its time. It worked. Based upon the non-emissions 6.0L that preceded it, the 6.4 was actually a clean-sheet design that shared almost no parts with its predecessor. The 6.0 had had a very rocky start in 2003-2004, with warranty problems galore. A mad scramble by Ford and Navistar greatly improved the 2005-2007 6.0’s, but the damage to Ford’s reputation was done. The 6.4 replacement was loudly pre-announced in 2007 as all-new and thoroughly tested, and 2008 model year production was begun about six months early. Aside from the relatively miserable fuel mileage caused by the new emissions systems onboard, the 6.4 diesel, a $6,000+ option, sold reasonably well, with Ford marketing doing everything possible to convince buyers that the bad times were over.
And they seemed to be. The 6.4 was considerably more powerful than its predecessor, and yet relatively free of the typical loud diesel clatter. Over time though, these engines too began to produce cataclysmic failures at too high a rate, and worse, proved difficult to repair without throwing something else out of whack. Once one problem was addressed, the situation too closely resembled a game of musical chairs, with another problem surfacing before too long. The complexity and inter-dependency of the various power and emissions systems invited either a misdiagnosis or a chain reaction. It may have been a clean-sheet design, but like the 6.0, internal fuel leaks and blown head gaskets occurred too often. The massive water pump and cooling system, oversized as part of the way to deal with extra heat from the emissions system, was so large in diameter that it became prone to cavitation: turbulence causing erosion of the pump wall, eventually allowing coolant to leak into the crankcase oil. Not good. (There is a Ford Coolant Additive VC-8 that is considered to control this erosion, though Ford does not mention this issue on the bottle or in Motorcraft product promotions.)
In essence, the 6.4 is unusually maintenance-sensitive. Ignore it or abuse it, or suffer some bad luck that requires major surgery, and you’re going to become a statistic. Pamper it and pay attention to what you’re doing with it, and you’ll never know what all the whining was about. For its day, it was a very stout and quiet powerplant. But it will not tolerate bad behavior. The abusive or indifferent owner can expect a major failure at anywhere over 125,000 miles, which is just awful for any engine, let alone a diesel. The typical owner trying to save a buck here and there can’t expect to go much beyond 180,000 miles. Still pathetic, especially for an engine with such an initial cost premium. And yet, some small but significant percentage of 6.4 owners are crossing over into traditional diesel lifespan territory without a speck of trouble. How? As it turns out, it isn’t blind luck, good juju, or the happy fortune of innocents. Four hurdles to cross appear to be essential here, and three of them relate directly to the owner.
The first is lucking out with an engine free of assembly problems from the start: good parts assembled correctly by Navistar before it ever got to the Ford truck assembly line in Kentucky. That’s essential because, if the engine must ever be torn into later, some other system is likely to be compromised in the process. The most common problems here tended to center around leaks in the high pressure fuel system. Once these engines were opened up to fix that problem, that tended to precipitate others, because the relationship between system componentry is quite finicky. Not crazily so, but let’s just say that it apparently helps to have a mechanic with an obsessive-compulsive disorder.
The second hurdle is maintaining the engine per the published maintenance schedule – at bare minimum. Coolant is the only sure exception, and the original change interval needs to be chopped in half whether it is chemically monitored or not. Between that and Ford’s VC-8 Coolant Additive, there’s a fighting chance. A second exception, the engine oil, needs to be monitored for fuel dilution, which is a problem related to how the “new” emissions system works. Many 6.4 owners find that instead of their truck burning oil between changes, the oil level on the dipstick actually increases over time, sometimes by a lot. Since fuel dilution decreases the lubricating properties of engine oil, the degree of dilution needs to be monitored. Failing that, normal oil change intervals need to be cut in half as a precaution. Finally, the 6.4’s fuel delivery components have proven to have an especially low tolerance for contaminants and rust. There are two fuel filters that are scheduled for replacement every 20,000 miles. This interval is best halved as well. Finally, ultra-low sulfur diesel fuel has been Federally mandated for all emissions-controlled diesels made since 2007, mainly since sulfur in regular diesel fuel will quickly damage emissions equipment. That would be all well and good, but ultra-low sulfur diesel fuel does not lubricate fuel injectors as before. That’s bad, because fuel injectors are not only breathtakingly expensive in themselves, but can fatally damage the engine when they malfunction. Any fuel additive that can lubricate the injectors will delay sticking and keep power levels high.
The next hurdle is no less critical. The 6.4 can use its available power freely, but not excessively. It’s the emissions systems again. Heavy use generates heat that the cooling system can and does dissipate, but a steady diet of this, combined with an emissions system that occasionally dumps extra fuel into the last two cylinders to bake the diesel particulate filter clean, will fry pistons and break rings if the throttle is held down without mercy. The owners manual simply cautions not to load the engine heavily while the dash panel displays that the engine is in “Regen” mode. Clogs, malfunctions, and component failures anywhere within any system can also add heat. The problem with excessive heat is that it’s usually localized, while the cooling system for it works on averages. It’s like a home air conditioner, which can handle the heat load added by a stove, but can’t keep you from burning the eggs in your pan. If you’re lucky, a sensor on the 6.4 picks up a potentially serious problem and cuts driveability to save the engine. Should you ignore the cut and/or the dashboard display, you will pretty much pay for that privilege. The great majority of the more spectacular failures that can be suffered by the 6.4 begin with a dashboard light and/or text message, and an audible chime to get attention. What the driver decides to do about those warnings then determines the difference between inconvenience and financial disaster. Understandably, employees driving fleet vehicles may find this decision to be a test of their personal values and priorities. One would think that an owner/driver would err on the side of caution, and most do. Some do not, however, and get a grim pleasure from beating a dead horse. They in essence punish the truck for complaining, and then deny any responsibility for what results. I’ve observed this.
The last hurdle is no less important to the 6.4, and that is to avoid “race tuning” computer swaps that add a lot of power output. They are wonderful, but only for awhile. Then the added heat destroys the engine. The usual regimen of deleting the diesel particulate filter works on this engine (so long as you also program out its presence on the vehicle’s computer) and helps the engine to last longer. You won’t find any shop to do this, however, since they’d be violating Federal law. EGR or Exhaust Gas Recirculation systems are also commonly removed or blocked off because when they do fail, they can dump enough coolant into either rear cylinder to hydrolock it. But removing it on the 6.4 can create new problems and is advised against by some shops when long life is the goal. Regardless, I think I can safely say that the majority of 6.4’s that suffer early catastrophic deaths and affect the 6.4’s poor reputation the most are A] those owners that have altered their 6.4s for more power and then tow trailers with them, and B] those drivers who press on in spite of dash warning alarms. Group A contains a sizable percentage of Super Duty diesel owners, making the odds of finding a used 2008-2010 diesel F-250 in sound mechanical condition a losing proposition. A stack of stellar maintenance records and lab test results are about the only thing that can help.
If It’s Broke, Don’t Fix It
It does not help that Navistar, as a result of its constant internal disputes with Ford, has changed the landscape on availability for many 6.4 replacement/rebuilt parts. Used major parts in rebuildable condition are scarce. It does not help that Navistar parts are nearly twice the cost of those from both the earlier Navistar 6.0 and the current all-Ford 6.7L. Nor does it help that the complex design itself makes a shop rebuild unlikely to succeed without reassembly problems. That problem has made it necessary for Ford to offer an unusually complete, drop-in rebuilt twin-turbo 6.4 engine assembly 8C3Z-6007-BARM that has everything that’s fastened or bracketed to the motor except a vertical EGR cooler. All the interdependencies are completed, and it’s warranted for two years by Ford, with no finger pointing possible. The current price is $15,100 (varies with the vendor selected) as long as the old engine is traded in (regardless of condition). Shipping and installation probably pump the total to over 20-grand. That’s a heap of money, exceeding the value of my whole truck. The only reason I could see for doing that is if the rest of the vehicle is holding up great (which is common) and you want to avoid playing Russian roulette in the used car lot. Trucks aren’t usually sold off unless there’s a good reason, and that reason is usually a significant mechanical problem. Last but not least, you also have to be willing to cease your sinful ways and maintain it with religious fervor this time around, or the replacement won’t last either.
All of these issues have had two effects for 2008-2010 6.4 Super Dutys. The first is that the resale value of these specific vehicles is reputed to be the biggest drop of any other Ford diesel, including the 6.oL. The second is that it literally pays to monitor what you can about your vehicle’s ongoing condition. Know when to hold ’em, and know when to fold ’em. If you can catch developing problems early as part of your maintenance regimen, you can usually fix them before they become a truly costly event. If a problem is developing which you know you cannot afford to fix, then you can get any remaining value out of the vehicle and replace it before it gets a chance to fail. Either way, maintenance and lab testing extract maximum usage out of the vehicle at the lowest cost. Any maintenance and testing costs I might incur are substantial, but are still peanuts compared to the costs involved with diesel engine work.
So Cut to the Chase, Already!
With all of the above in mind, my future with the Mighty Furd pretty much comes down to finding out how healthy it is under all that shiny but scratched paint. Here’s the oil sample test report that Blackstone Labs emailed me:
My engine mileage is 104,200, while the miles on the oil are 4,200. Ford recommends oil changes at 10,000 miles for normal conditions and 5,000 for severe conditions (dust or lots of low-speed work or idling). The two viscosity test methods as well as the “TBN” test indicate that the oil is holding out just fine as far as its additives go, at the current miles. The only concern is a fuel dilution of 2.5% when this engine should preferably be somewhere less than 2%. Some fuel dilution is inevitable in the 6.4, resulting mainly from extra fuel dumped into the rearmost two cylinders when the DPF is in regeneration mode, and simple blowby past the piston rings. The dashboard readout once signaled when the system kicked into regeneration mode, but the last firmware update changed that to only a momentary text display without any hint at how long the mode lasts. The full benefit requires staying at speed until it completes, which can take well past half an hour. An interrupted regeneration tends to spawn more later, thinning out the oil further. Extended idling or stop & go traffic can also add fuel, though the main hazard of idling is to ruin the EGR system. Using fuel with any more sulfur than specified is known to increase fuel dilution. The use of biodiesel can be a contributor as well, especially since most such stations list the percentage as “up to 20%”. My 2008-2010 series risks emissions system damage at over 5%, and sometimes there’s no choice, particularly in states having a vested interest in corn crops. This is hardest on owners of certain F-350s and up that use certain fuel tank types, because high-percentage biodiesel can cause leaks in them. The most sinister potential cause of dilution is leakage at connections along the extreme high pressure fuel rail system inside the engine. It can leak large amounts without being detected. In my specific test results, a dilution of 2.5% is not yet a problem, but is “of concern” and is worth monitoring in the future. A plug-in gizmo to signal when a regeneration is in progress is also worth considering, since it has the potential of lowering dilution and thus lengthening expensive oil change intervals.
Apart from my fixation on fuel dilution, the lower boxes also show no contamination from antifreeze or anything else, indicating that the head gaskets are holding tight. The upper boxes indicate that wear levels are better than average when compared to the glut of 6.4s at this mileage, represented by the “Universal Averages” column to the right. The “Unit/Location Averages” column is useless at this point, since it’s meant to show an average of all tests conducted on my truck over time, of which I have only one. Each element on the list tends to be added into certain engine parts more than others, in order to enhance the qualities those particular parts need. As the engine wears, they tend to show up in the lubricating oil. Blackstone has enough experience to recognize where these elements come from, so an excess of one might prompt them to write, say, that the rocker arms (another trouble spot with the 6.4) are wearing faster than normal. Fortunately for me, all wear levels are either normal or less than normal, signalling that I should keep doing what I’m doing. As long as I stick to certain regimens and practices that have proven to help the 6.4 last (which do not include swinging a chicken over one’s head at midnight during the Russian Solstice), then it’s quite possible that the ten-year-old Mighty Furd might make it to twenty or more, which had been my expectation at the start. Little did I realize then what challenges the new Federal emissions standards would present, or just how badly longtime supplier Navistar would fumble the ball! While the initial 6.0 problems tested the Ford-Navistar corporate relationship to its limits, the 6.4 experience ended it, convincing Ford that it must roll its own if it ever hoped to regain its trashed reputation in the fleet and trade markets. That’s a very costly proposition to carry out in a niche market where pickup trucks would normally be just one application in a much broader market for the same engine design.
What’s the Plan, Hey?
One thing’s for sure. I’ll keep monitoring the Mighty Furd’s oil over time, to keep tabs on that fuel dilution, as well as any standout wear points. I’ll likely go ahead and change the oil at the 5,000-mile mark in order to “start over” with dilution, and see if a ScanGauge II diagnostic device can let me know whenever a DPF regen is in progress. It’s only too bad that, for whatever reason, Ford decided to back down on displaying that on their built-in readout.