Dozens of new Ford Bronco owners report critical issues with their trucks’ 2.7-liter EcoBoost V6 engines. They fail with low miles – under 10,000, so it seems – and are sent to dealers, where repairs can take months. The whisper of these questions hit first Bronco6G forums in July 2021, although a thread telling about ownership testimony has grown to include 46 affected offroaders at the time of publication.
With the list expanded by the week, The drive contacted Ford for a comment. A spokesman for the automaker explained: “We are aware of a select number of engines with this concern and we are investigating. If any customers experience problems, they will be covered by the vehicle’s 5-year, 60,000-mile driveline warranty.”
This confirms that Ford at least acknowledges the situation. But what should Bronco owners look for?
The first user-reported problem involved a Bronco with 1,146 miles on the odometer, and it was eventually attributed to a lost valve – meaning the head of one of the engine valves was separated from the trunk and eventually dropped into the cylinder. This immediately results in a loss of compression, but also sends a chunk of metal into the cylinder, which can lead to catastrophic results.
To be clear, the engine we are talking about here is Ford’s second generation 2.7-liter EcoBoost. Currently, it is only found in the Ford Bronco and F-150, but most bug reports have been limited to the Bronco; some F-150 owners have also reported errors, but this was significantly less common throughout our research into the case. The first generation 2.7-liter is still used in some Ford and Lincoln vehicles, although these do not appear to be affected.
The forums remained relatively quiet for a few months after the first report, but in October, several threads with defective engines began to appear. Other owners volunteered over the following months, many of them noting that their Broncos had also lost a valve, resulting in an engine replacement.
Besides Bronco6G thread, which also accounts for complaints spotted in various Facebook groups, there are several Reddit threads showing the Broncos equipped with the 2.7-liter reportedly suffering from the same issues. One member posted a Facebook screenshot from one who noted that a Facebook group that was only for technicians had seen about 30 faults in Bronco engines in a month’s time.
The National Highway Traffic Safety Administration also has a number of complaints about Bronco on its website. Of the 42 registered complaints, more than half involve the SUV’s engine. A staggering 20 of the 25 engine-based complaints refer to complete faults, many of which specifically indicate a problem due to a lost valve.
In October 2021, one was now deleted Bronco6G account published that the defects were attributed to a bad batch of valves, which Ford received from one of its suppliers. The account claimed to be working at the Lima engine factory, where the 2.7-liter is produced, noting that the bad valves were mostly contained in an April batch. The user stated that something in the metal composition of the valve became brittle by engine heat over time, and stressed that it was a supplier problem.
Interestingly, a note in Ford’s “State of the Plant” bulletin of January 2022 for its Lima plant notes that a supplier problem was solved with its Nano engine – the 2.7-liter found in the Bronco. More specifically, a more robust valve design and material changes are mentioned, which are similar to the posts from the deleted user on Bronco6G.
It is difficult to say how many Broncos may be affected, as the construction date of included engines appears to extend over months rather than weeks. For example, the thread on Bronco6G tracking the bugs is also tracking the build date of the faulty engines, which range from May 2021 to October 2021. Ford sold more than 20,000 units of the Bronco in the US and Canada during that time frame, even though the tariff rate was 2.7-liters V6 vs. the 2.3-liter four-cylinder is not readily available. It is not clear whether the April batch of valves was used until October 2021, or whether the allegations from the suspected Lima employee hold water. The highest mileage on a reported fault is 6,986 miles, while the lowest is only 984 miles.
Some affected owners report that they are being compensated with a longer driveline warranty, and others praise Ford for how they handle the problem by working closely with affected customers despite the long repair time. However, some want a broader effort to protect other owners from potential errors by urging NHTSA’s Office of Defects Investigation to open an investigation into the errors.
Whether or not a defective investigation is opened into these issues, this can be a major flaw in a flagship Ford product. After all, a catastrophic engine failure is not like a small component that fails – it is the heart of the vehicle and a rather expensive system of parts to replace. The people at Bronco6G asks affected owners to file a complaint to NHTSA if their engine fails in a similar manner, and suggests reporting the issue to the user who tracks the bugs on its forum.
Do you have a tip or question for the author? Contact them directly: rob@thedrive.com