Dozens of Low-Mile 2.7L Ford Bronco Engines Have Already Failed

Ford says it is aware of a “select number of engines” with this concern.

byRob Stumpf|
Ford News photo
via Ford


Dozens of new Ford Bronco owners are reporting critical problems with their trucks' 2.7-liter EcoBoost V6 engines. They're failing with low miles—under 10,000, by the looks of it—and are being sent to dealers where repairs can take months. Whispers of these issues first hit the Bronco6G forums in July 2021, though a thread chronicling owner testimonies has grown to include 46 affected off-roaders at the time of publishing.

With the list expanding by the week, The Drive reached out to Ford for comment. A spokesperson from the automaker explained, "We are aware of a select number of engines with this concern and we are investigating. If any customers are experiencing issues, they will be covered under the vehicle’s 5 year, 60,000-mile powertrain warranty."

This confirms that Ford is at least acknowledging the situation. But what should Bronco owners be looking for?

The first user-reported issue involved a Bronco with 1,146 miles on the odometer, and it was ultimately attributed to a dropped valve—that means the head of one of the engine's valves was separated from the stem and ultimately dropped into the cylinder. This immediately results in a loss of compression, but also sends a chunk of metal into the cylinder that can lead to catastrophic results.

To be clear, the motor we're talking about here is Ford's second-generation 2.7-liter EcoBoost. Presently, it's only found in the Ford Bronco and F-150, but most reports of failures have been limited to the Bronco; some F-150 owners have reported failures as well, but it was significantly less common throughout our research on the matter. The first-generation 2.7-liter is still being used in some Ford and Lincoln vehicles, though these do not appear to be affected.

The forums stayed relatively quiet for a few months after the first report, but by October, more threads of failed engines began popping up. Other owners chimed in over the following months, many of them noting that their Broncos had also dropped a valve, resulting in an engine replacement.

In addition to the Bronco6G thread, which also accounts for complaints spotted in various Facebook groups, there are several Reddit threads showing Broncos equipped with 2.7-liters allegedly suffering from the same issues. One member posted a Facebook screenshot from someone who noted that a technician-only Facebook group had seen approximately 30 failures of Bronco engines in a month's time.

The National Highway Traffic Safety Administration also has a number of complaints about the Bronco on its website. Of the 42 recorded complaints, more than half involve the SUV's engine. A staggering 20 of the 25 engine-based complaints reference complete failures, many specifically indicating a problem resulting from a dropped valve.

In October 2021, a now-deleted Bronco6G account posted that the failures were attributed to a bad batch of valves that Ford received from one of its suppliers. The account claimed to work at the Lima engine plant where the 2.7-liter is produced and noted that the bad valves were mostly contained to an April batch. The user stated that something in the valve's metal composition became brittle from engine heat over time, and stressed that it was a supplier issue.

Interestingly, a note in Ford's January 2022 "State of the Plant" bulletin for its Lima facility notes that a supplier issue was resolved with its Nano engine—the 2.7-liter found in the Bronco. More specifically, it mentions a more robust valve design and material changes, which is similar to the posts from the deleted user on Bronco6G.

It's hard to say just how many Broncos might be affected, as the build date of included engines appears to span months rather than weeks. For example, the thread on Bronco6G that is tracking the failures is also tracking the build date of the failed engines, which range from May 2021 until October 2021. Ford sold more than 20,000 units of the Bronco in the U.S. and Canada during that timeframe, though the take rate on the 2.7-liter V6 vs. the 2.3-liter four-cylinder isn't readily available. It's not clear if the April batch of valves was being used until October 2021, or if the claims from the supposed Lima employee hold water. The highest mileage on a reported failure is 6,986 miles, while the lowest is just 984 miles.

Some affected owners are reporting that they are being compensated with a longer powertrain warranty, and others are praising Ford for how they are handling the issue by working closely with affected customers despite the lengthy repair time. However, some want broader action taken to protect other owners from potential failures by calling on the NHTSA's Office of Defects Investigation to open an inquiry into the failures.

Whether or not a defect investigation is opened regarding these issues, this could be a big blemish on a flagship Ford product. After all, a catastrophic engine failure isn't like a small component failing—it's the vehicle's heart, and quite an expensive system of parts to replace at that. The folks at Bronco6G are asking affected owners to file a complaint with the NHTSA should their engine fail in a similar way and suggest reporting the problem to the user tracking the failures on its forum.

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