The Most Reliable EcoBoost Engine Ford Has Ever Produced
Ford's EcoBoost engine suffered from a rather rough start to its life. When it was first introduced in 2009, the first iterations of the motor family were known for running too hot, leading to premature wear and catastrophic failures. But, what the EcoBoost did do, was pave the way forward where vehicles such as pickup trucks no longer needed huge V8s with generally poor fuel economy to do the job. A turbocharged six-cylinder unit would do.
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Ford
Ford is one of America's oldest automakers and one of the oldest in the world, popularized for being the first to effectively mass produce the automobile under Henry Ford with the Ford Model T. In over 120 years, Ford has become a sales leader in a variety of segments, with popular nameplates like the Ford F-150, Transit, and Mustang.
The EcoBoost engine family was still plagued with issues for the most part, despite their promise. However, just a handful of years ago, Ford finally sat down and worked some issues out with one problematic EcoBoost motor in particular. The engine in question is the 3.5-liter EcoBoost V6, which, following its 2018 gen-two refresh, has become the most reliable EcoBoost motor on Ford's offering list to-date.
Ford 3.5L EcoBoost V6 Engine
The 3 Versions Of Ford's 3.5-Liter V6 EcoBoost Explained
Three generations of the Ford 3.5L EcoBoost V6 exits. Here's a breakdown of each generation.
We chose the gen-two 3.5-liter EcoBoost V6 based on its overall customer-reported reliability, courtesy of Ford vehicle reviews.
The 3.5-Liter EcoBoost Has Come A Long Way
2013 Ford F-150 White Front Angle Farm Driving
2018–Present 3.5-Liter EcoBoost V6 Key Points
- Introduced in 2018
- Debuted in the Ford GT
- Featured upgrades to its valvetrain and fuel system
- In production as of 2025
- Also referred to as the "D35"
The D35 3.5-Liter EcoBoost features quite a few key upgrades over its predecessor, whose unreliability was highly-publicized, especially early on in its life. However, the second generation 3.5-liter EcoBoost is generally regarded as the most reliable Ford EcoBoost motor. Ford, determined not to let the ill-fated 3.5-liter EcoBoost name die out, decided to get back to the drawing board and use the lessons learned from the first-gen to make a better motor.
Why The Second-Gen Is Much More Reliable
One of the largest issues that plagued the original EcoBoost 3.5-liter V6 - the motor that ended up helping to contribute to the EcoBoost's current bad reputation as a whole - was its valvetrain. More specifically, the earlier 3.5-liter EcoBoost V6 used a single primary camshaft chain, a component known for stretching over time. Ford replaced it with a twin-chain design, so instead of one chain operating two cylinder banks, one chain was used for each. This solution alone was a large driving force behind minimizing timing chain stretch.
The second-gen now also features port fuel injection alongside direct injection. This was done in order to help curb carbon buildup, a common issue among turbocharged engines, especially those tasked with consistent heavy load. Because of how port injection works, such as splashing fuel over the top of the motor's valves, it helps to clean the engine of the buildup, and maintain an overall cleaner head.
A third major change was to its turbochargers. Its pair of Borg Warner turbos received lightweight turbine wheels made out of something called Mar-M-247 super-alloy, which improves turbocharger responsiveness and, in turn, better throttle response. The more responsive turbochargers helped to ease operating temperatures, as the turbos don't need to spend as much time operating at maximum capacity if power is delivered quicker.
Roots Steeped In Uncertainty
2017 Ford Flex Exterior
When the first 3.5-Liter EcoBoost V6 first hit the streets back in 2010 and kicked off Ford's use of the now-famous nomenclature, the promise of a powerful motor capable of performing nearly as well as a V8 without suffering from the typical eight-pot fuel economy was exciting. However, quickly, things took a turn for the worse as issues with the motor's camshaft phasers, timing chains, and cooling began to plague a slew of 3.5-liter EcoBoost V6-equipped vehicles. It was so bad that the motor was swiftly deemed unreliable by the motoring public.
The bones of the original and D35 EcoBoost V6 are based on the Duratec 35 V6 engine, a fastidiously-reliable mill produced by Ford. However, due to the nature of the EcoBoost's turbocharging and expected high-load usage, the rest of the motor is virtually unrelated. Apart from the issues listed above, the original 3.5-liter EcoBoost V6 also saw problems with misfiring due to carbon buildup on its spark plugs, heavy coolant leaks around the motor's water pump, and turbo intercooler condensation, which ends up limiting the cooling capacity of the intercooler, forcing the turbochargers and, in turn, engine to run hotter than it should.
The Most Reliable EcoBoost Runner-Up
ford fox 1.0-liter 3 cylinder
The second-most reliable EcoBoost motor isn't even made for the US market. It's the 1.0-liter three-cylinder EcoBoost, nicknamed "Fox". It's seen widespread use in Ford's UK market in models such as the Puma, Fiesta, Focus, and Mondeo. Despite its tiny size, it's able to produce up to 170 horsepower and 183 lb-ft of torque in the Ford Puma ST. It's also been used in rally racing in both the Ford Fiesta Rally4 and Fiesta Rally5 race cars. Production of the motor began in 2012 and is still underway as of this write-up.
However, the Fox has suffered from one glaring issue throughout its tenure. Its valvetrain uses a timing belt, rather than a chain. This belt, or "wet belt" tends to stretch badly after some time, leading to catastrophic motor failure. The Fox is also prone to overheating, as its nylon coolant pipes tend to fail at high mileage and, if not caught early enough, can lead to overheating and warping of the cylinder head or worse, a cracked engine block.
Despite these issues, both of which carry risk factors that can be significantly reduced with proper maintenance, as per Ford, the Fox motor is seen as generally reliable. In fact, it's the EcoBoost motor with the fewest number of recalls, something that Ford should wear proudly, considering they've seen their fair share of recall bulletins over the past year or so.
Sources: Ford, Ford UK, NHTSA, CarSurvey.org, Full-Race.com
