Ford's 3.5-Liter EcoBoost Engine: Which Years Should You Avoid (According To Owners)

Ford's range of EcoBoost engines — which include all sorts of engines with three, four, and six-cylinder layouts — are used in a huge amount of different models, with some sporting award-winning technology, and all adorning turbochargers. The EcoBoost engine likely comes as Ford's answer to the growing popularity of downsizing, which sees automakers swapping out old, big capacity naturally aspirated engines for smaller, turbocharged, and more efficient units.

One example from Ford's expansive catalog of models is the F-150, America's favorite fullsize pickup truck. Whereas many iterations of the mighty F-150 have traditionally sported V8 engines, more recent generations have instead opted to use the 3.5-liter EcoBoost V6, while 2025 Ford F-150 models now use a 2.7-liter EcoBoost V6 in the hybrid version, further showing how downsizing has affected the pickup truck's methods of motivation over the years.

The F-150 isn't the only Ford to have made use of the 3.5-liter EcoBoost engine either. Even the brand's flagship supercar was powered by a different variation of the EcoBoost V6, which can be seen in our first drive of the Ford GT, as was the Explorer, Expedition, and Transit. However, not every Ford model powered by the 3.5-liter EcoBoost V6 engine has proven to be reliable, with owners on Reddit complaining about timing chain problems, cam phaser failures, and a whole raft of other reliability concerns. Not all model years are affected though, and we've highlighted below the iterations which are proving most troublesome.

In order to establish which years of the 3.5-liter EcoBoost V6 engines are the worst, we looked at what owners had to say, and compared the data. Over on the Ford F-150 forum, many are happy to defend the 2015 and 2016 units, but do have concerns regarding engines produced either side of these two years. One owner says "I think the 15-16 3.5 Ecoboost is the most problem free out of all the years. 11-14 had condensation issues. 17-19 have cam phaser, rattle noise issues", while another forum user built upon this by saying "an 11-12' on the original timing chain might concern me".

It would appear that the threat of a timing chain issue concerns a huge number of V6-powered F-150 owners, with one owner on the F-150 Ecoboost forum claiming "I would say 100% of 11-14's would have a problem with the timing chain, it's a design flaw!" after having to replace a rattling chain on their 2012 model around 80,000 miles. Looking at owners comments, though, it would suggest that model churned out in 2015 and 2016 were significantly more reliable, as many owners report being able to achieve high mileages without any issues. They do, however, state that frequent oil changes with the correct grade oil is imperative for keeping the EcoBoost V6 in good health.

While the timing concerns were ironed out, meaning owners are happy to get behind the wheel of 2015 and 2016 EcoBoost-powered Ford models, the model years which followed began to suffer from costly cam phaser problems. A quick search of the F-150 Forum reveals a wide range of owners who have experienced such problems on 2017-2020 model-year trucks, with cam phasers having to be replaced multiple times.

There are many who fortunately had the repairs carried out under warranty, which saved them from bills of $3,800, but as the models age, fewer and fewer cam phaser repairs are likely to be covered by the manufacturer, which means huge bills will be coming for new owners. Despite these model years sporting up to 17 recalls according to the NHTSA, the administration details no action taken to rectify the cam phaser issue, and without a recall to cover the costs, it looks increasingly likely that cam phaser failure bills will be handed directly to the owners once warranty periods are over.

In an effort to keep customers satisfied, Ford announced that they would "extend warranty coverage until January 1, 2023, for cam phasers that develop undesirable noise in vehicles equipped with a 3.5-liter gasoline turbo direct injection (GTDI) engine. Those vehicles include 2017-2020 Ford F-150 3.5-liter EcoBoost engines, 2018-2020 Expedition, 2018-2020 Navigator and the 2017-2020 F-150 Raptor/Limited variants". Ford has since updated the design of cam phasers for the EcoBoost V6.