Dozens of new Ford Bronco owners have reported serious problems with their truck’s 2.7-liter EcoBoost V6 engine. They break down due to low mileage — it looks like they have less than 10,000 miles — and it can take months to get to a dealer for repairs.Rumors of these problems first hit Mustang 6G Forums in July 2021, although the thread recording owner testimony at the time of posting has grown to include 46 affected SUVs.
As the list expands every week, driver Contact Fortune for advice. A spokesperson for the automaker explained: “We are aware of some engines having this problem and we are investigating. If any customers experience a problem, they will be covered by the vehicle’s five-year, 60,000-mile powertrain warranty.”
This confirms that Ford has at least acknowledged the situation. But what should Bronco owners be looking for?
The first user-reported issue involved the Bronco with 1,146 miles on the odometer, which was ultimately attributed to a valve drop — meaning the head of one of the engine’s valves separated from the valve stem and ended up in the cylinder. This results in an immediate loss of compression, but also sends a chunk of metal into the cylinder with disastrous results.
To be clear, the motor we’re talking about here is Ford’s second-generation 2.7-liter EcoBoost. Currently, it’s only found in Ford Bronco and F-150, but most fault reports are limited to Bronco; some F-150 owners have also reported faults, but in our research on the matter, this is significantly less the case common. The first-generation 2.7-liter engine is still used in some Ford and Lincoln vehicles, although these don’t appear to be affected.
The forum was relatively quiet in the months following the first report, but by October, more posts about the failing engine began to appear. Over the next few months, other owners have said that many of them pointed out that their Broncos also lost a valve, leading to an engine replacement.
Apart from Mustang 6G The thread, which also explains the complaints found in various Facebook groups, has several Reddit threads showing that the 2.7-liter-equipped Broncos allegedly had the same problem. A Facebook screenshot was posted by a member who noted that a tech-only Facebook group saw about 30 Bronco engine failures over a one-month period.
The National Highway Traffic Safety Administration also has numerous complaints about the Bronco on its website. Of the 42 complaints recorded, more than half involved the SUV’s engine. Of the 25 engine-based complaints, a staggering 20 involved complete failures, many of which specified problems caused by dropped valves.
In October 2021, a now deleted Mustang 6G The account posted that the failure was due to a batch of inferior valves Ford received from one of its suppliers. The account claims to work at the Lima engine plant that makes the 2.7-liter engine, noting that the damaged valve was mostly contained in the April batch. Users say that over time, something in the metal components of the valve can become brittle from engine heat, emphasizing that this is a supplier issue.
Interestingly, Ford noted in its January 2022 “Condition of the Plant” bulletin for its Lima plant that the supplier issue has been resolved with its Nano engine (the 2.7-liter engine found in the Bronco).More specifically, it mentions more robust valve design and material changes that have been removed from users in Mustang 6G.
It’s hard to say how many Broncos might be affected, as build dates for the included engines appear to span months rather than weeks.For example, on the thread Mustang 6G The failure is being tracked along with the manufacturing date of the failed engine, which ranges from May 2021 to October 2021. During this period, Ford sold more than 20,000 Bronco units in the United States and Canada, although the 2.7-liter V6 with the 2.3-liter four-cylinder engine was not readily available. It’s unclear if the April batch of valves will be in use until October 2021, or if the hypothetical Lima employee’s claims hold true. The highest mileage reported as a breakdown was 6,986 miles, while the lowest mileage was only 984 miles.
Some affected owners reported they were getting longer powertrain warranties, while others praised Ford for handling issues by working closely with affected customers despite the lengthy repair times. However, some hope to take broader action to protect other owners from potential failures by calling on NHTSA’s Defect Investigations Office to investigate the failure.
Whether or not a defect investigation is launched for these issues, this could be a major flaw in Ford’s flagship product. After all, a catastrophic engine failure isn’t like a small component failure — it’s the heart of the vehicle and requires replacing a rather expensive system of parts.people are Mustang 6G If their engine fails in a similar fashion, affected owners are asked to file a complaint with NHTSA and are advised to report the problem to users who track the failure on their forums.
Have a tip or question for the author? Contact them directly: rob@thedrive.com