Signs point at oil starvation, but there's more to it.
Engine teardown specialist and YouTuber I Do Cars recently got his hands on a twin-turbo 2.7-liter EcoBoost V6 from a Ford F-150. In the video detailing his disassembly, we discover clues on what caused it to fail at 96,000 miles on the odometer.
According to the viewer who donated the engine, the truck's oil pressure warning light came on as he was traveling on the highway. Upon opening the trunk, he found that the engine puked oil over the right side of the engine bay. Its dipstick was also sticking out.
During the teardown, no damage can be discerned, and according to Eric, the V6 turned over just fine. The spark plugs were in good condition; the same goes for the valvetrain components.
After removing the plugs, he had a hard time turning the camshafts. He also found that the oil filter for the passenger-side turbo and the engine's timing chain cover was full of metal bits. Like the 2.0-liter mill from an EcoSport, this EcoBoost comes with an oil pump belt made out of rubber, which is bad for longevity.
The camshaft and journals also showed wear, but that's par for the course considering its mileage. However, one of the pistons on the first bank looked like it made contact with the cylinder head and showed a fair bit of looseness. The other side, meanwhile, had rougher cams, but its cylinders, pistons, and head looked alright.
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It got worse when the oil pan and rods were inspected. Plenty of metal shavings were mixed in with these components, and particularly large pieces were found inside the oil pump. Even worse, one of the rods had plenty of play and was shaking around.
So where did those metal bits come from? Well, one of the rod bearings had spun. The other bearings were also in poor condition and showed signs of oil starvation. Then again, Eric admitted that he still doesn't know what pushed the dipstick back when the engine spewed out engine oil. There's a chance the dipstick not being secured properly allowed oil to overflow, resulting in starvation, or it the dipstick could've been the symptom rather than the cause.
The YouTuber noted that the latter usually happens in turbocharged engines if their ventilation systems are compromised. This wasn't the case here, but still, he says something was wrong with the parts inside the crankcase.
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Keyword: Engine Teardown Shows Why Ford F-150's EcoBoost V6 Died At 96K Miles