Ford EcoBoost V6 engines are found in a variety of Blue Oval vehicles, though the F-150 is certainly the most prominent of them all. The 2.7-liter EcoBoost makes 325 horsepower under the hood of Ford's popular truck, but we suspect the engine featured in this I Do Cars video makes a bit less than that.
The 45-minute clip is basically an automotive murder investigation where the only source of information is the condition of the victim. This engine was a core return, pulled from a 2015-2017 F-150 for reasons unknown. The mileage is unknown, and it's unclear if the six-pot was subjected to aftermarket tuning. On the outside, at least, it appears to be 100 percent factory stock.
The story begins with the engine on a stand, still completely buttoned up and showing no signs of foul play. It turns over by hand without making interesting noises and still exhibits compression. The first clue comes with the discovery of an electrical connector undone on a coil for one of the spark plugs. Furthermore, it appears the three spark plugs from that cylinder bank were removed and reinstalled at one point. However, all the plugs look factory original, suggesting the engine has less than 100,000 miles.
The disassembly continues. The sprawling wiring harness is removed, followed by the intake plenum and turbochargers. It's at this point we start seeing puzzle pieces connect, as one turbo shows small metal flakes in a mesh filter. Speaking of filters, the oil filter is removed and cut open, revealing even more bits of metal. Clearly, something of significance failed within the engine.
The plot thickens. Removing the valve covers shows the dual overhead camshafts and valvetrain in good condition, though more small metal flakes are found in various spots. Furthermore, removing the timing chain cover reveals more sparkly metal bits in oily sections at the bottom of the housing, but the components are in good condition. Finally, the heads are removed and the first one – as with everything else in the teardown to this point – looks fine.
The second head finally reveals the issue, and it's not small. Technically speaking, the portion of the piston that's missing is small, but it doesn't take much to kill an engine. Per the video, it appears the cylinder was running hot enough to melt the piston. A portion of it literally melted into the cylinder wall, and once removed, it's easy to see the extensive damage to the piston. Similarly, the valves and combustion chamber in the head of that cylinder are also beat up.
It's unclear if the engine block is salvageable. Furthermore, though we know how this engine died, we still don't know exactly what led to this condition. The video doesn't offer a conclusion on that, aside from saying there are any number of reasons that could lead to a melted piston. The video also concludes that, after conducting a complete teardown, Ford's 2.7-liter EcoBoost seems to be a pretty good mill. From a manufacturing perspective anyway.
It's worth noting that Ford issued a Technical Service Bulletin (TSB) for the 2.7-liter EcoBoost of this era. Bad value guides in the heads could lead to rough running conditions and excessive oil consumption. The TSB calls for replacing both heads, though it's unclear if that has anything to do with the failure seen in this video.