My understanding is the 3.5ecoboost got added to the F-150 in 2011, is there a big difference between the early years and the more newer years? My thinking is I could probably pick up a used 3.5 ecoboost for a good price. As much as I'd love a new 2021, I'm thinking that would be cost prohibitive right now.
I'm near the SF bay area so gas prices are obscene right now.
The first gen 3.5 was 2011-2016. There was some minor changes during that time. In 2013 they got larger turbos, although the power rating stayed the same. Some of the issues with the 1st gen:
-Timing chain stretch. Ford used one long chain for both cylinder banks so it was more susceptible to stretch issues. Solution seems to be short oil change(5k or less) and making sure you get the truck hot once in a while. This does not happen to everyone and it seems to be an issue on trucks that dont get worked. We have seen some 400k mile trucks that towed every day for work that were still on the factory chain.
-Warped exhaust manifolds. Ford seems to have used the same manifold stud pattern as the non turbo V6. Its a terrible design and there is a big gap between studs toward the back of the manifold where the turbo is bolted on. Get it hot enough and they will warp. You can tell they warped because the rear most stud is usually snapped off. The manifolds will make a high pitched chirping noise when the truck is cold and you hit the gas.
2017 was the first year of the second gen and included some major changes:
-Dual injection. The 1st gen was only direct injected, the injector spray directly into the cylinder like a diesel. Second gens also have port fuel injectors. This helps mpg’s at low loads, but also washes the intake valves clean, which is an issue for direct injected motors
-Two timing chains. So now each bank gets its own smaller chain. Chain stretch is not an issue but they messed up the cam phaser design so there is that now, which may be fixed.
-redesigned exhaust manifolds. No more warped manifolds
-electronic wastegate actuators. Not a big deal but just gives the pcm much better control over boost.
-10 speed trans.
-Turbos might be slightly bigger than the 2013-2016 turbos.
In 2018 the 3.5L got even larger turbos to match the ones in the Raptor with the 450hp 3.5L. Again, no change in the power rating but this allows the truck to make full rated power right to 12000’+ of elevation.
The 2.7L got dual injection, the 10 speed, and a small torque bump in 2018
