When your everyday driving needs call for some serious hauling power, a used Ford equipped with the brand’s powerful 6.8L V10 engine may be just what you need. Still, as with any engine, Ford‘s V10 has run into some known imperfections over the years.
What are the most notable Ford 6.8L V10 engine problems?
Interestingly, they all have to do with the engine’s spark plugs, which apparently have a tendency to fall out or even be ejected from the engine while driving.
We’re covering this issue in-detail below, including some examples of real owner complaints that have been filed in regard to this problem. We’ll also provide an explanation of what causes this issue and what can be done about it if you’re considering a used Ford with a V10 engine as your next vehicle.
More About Ford’s 6.8L V10 Engine
Thanks to its extra cylinders and innovative design, Ford’s 6.8L V10 engine is one of the most capable that has ever been produced. With an output of up to 362 horsepower on some models, this engine has been manufactured in both two- and three-valve configurations.
Making its debut for the 1997 model year, Ford’s 6.8L V10 engine can be found on a number of models, ranging from the Ford Excursion to the Ford E350 and E450.
The V10 has also been found on a number of Ford’s motorhome models, as well as the 2005-2010 Ford Super Duty.
Common Ford 6.8L V10 Problems
2005 Ford Excursion: Detaching Spark Plugs
NHTSA Complaint ID: 10654556
In this NHTSA complaint filed in November of 2014, the owner of a 2005 Ford Excursion reports that the vehicle’s “check engine” light illuminated while driving at around 10 miles per hour. Upon taking the vehicle to a mechanic, it was found that the spark plugs had detached from their cylinder heads.
Even after replacing the spark plugs, the owner claims that this failure occurred a second time.
According to the complaint, the initial spark plug failure took place with approximately 140,000 miles on the odometer.
2005 Ford F-250 Super Duty: Ejecting or Stuck Spark Plugs
NHTSA Complaint ID: 11035371
A similar issue with spark plugs has also been reported on Ford Super Duty F-250 models equipped with the 6.8L V10 engine.
In one Vehicle History review posted in October of 2018, owner Nikki S. reports that her spark plugs have “exploded” while driving. Despite this problem, she still gives the vehicle a rating of 3/5 stars in her review.
Interestingly enough, an NHTSA complaint filed in 2017 reports the opposite problem in a 2005 Ford F-250. This owner claims that according to a mechanic, it will be difficult to replace the spark plugs as needed for routine maintenance due to a design flaw.
In this case, rather than the aluminum gaskets expanding and causing the spark plugs to eject, the plugs themselves actually become welded to the gaskets and can be near-impossible to remove.
What to Do if Your V10 Engine Has This Problem
If you buy a used Ford with a 6.8L V10 engine, there’s a good chance it has already run into this problem or will in the future. That’s because this issue is caused by a design flaw that allows the aluminum threads holding the spark plugs in place to expand and create gaps.
Over time, the threads holding the spark plugs in place can also weaken or become threaded, resulting in the ejection of the spark plugs themselves. Fortunately, Ford has issued repair kits to address this problem. It is also covered under Ford’s factory warranty.
If your used Ford is outside the warranty window and the threads have not already been replaced with proper steel inserts, consider bringing your vehicle to a Ford service center to have aftermarket threads installed. This will ensure that your spark plugs stay in place as they’re intended to.
