Originally Posted by Navi
Now keep in mind I very much enjoy the Lincoln Navigator and the Ecoboost engine. Im not knocking it and my current quest is to see what we can do to remedy these issues.
I dont think there is a one size fits all oil for all vehicles. Each oil has different properties and characteristics which will make the engine run the best or it might break the engine. The way we find out is through discussion and analysis of the various oils which is what this website is for.
The Amsoil Signature Series I ran made the truck run pretty well. The Shell Gas Truck oil made me worry as the engine was making noises and running rough. Now with this oil the engine feels strong and smooth. Of course those are personal seat of the pants opinions.
So let me get to the point. The solution to this problem is to find a shear stable oil. The vast majority of oils out there like Mobil 1, Quaker State, Valvoline, etc are simply NOT shear stable. I know they might be your favorite oil but they not good for your Ecoboost engine. If you run those oils you risk significant engine damage. They great for your Toyota but not a high horsepower blown or turbo engine!
The two shear stable oils are going to be those designed for diesel engines or a custom made high end oil. Thus why I am testing Amsoil 5W-30 Signature Series and Shell Rotella T6 5W30 MultiVehicle.
Now a lot of guys run T6 5W40 but I wont run it. The reason is the camphasers are actuated by hydraulic force and the engine oil acts as a hydraulic oil for those phasers. Those phasers are calibrated for 5W30. T6 5W40 also has higher phosphorus which Shell admits might damage your catalytic converter in a gas engine. Furthermore 40 weight might cause more wear at startup.
Neither Amsoil or Shell T6 5W30 MV is Dexos or certified by Ford. Its a bit of a nail bighter throwing it into the engine knowing that and you cant admit that to the dealer for warranty purposes. However it works!
On another note. Amsoil isnt Scamoil. I believe the various UOAs posted are evidence the Signature Series line of oils is a premium product.
Before replying to this take a moment to read this link which explains my logic and why I believe shearing is causing the camphaser problems.
https://www.enginelabs.com/engine-t...ion-should-you-run-higher-viscosity-oil/
I don't think you're problem is shearing, I think it's fuel dilution. There's not much that can be done about that, other than start with a thick oil. Redline has said previously on their website that their ester-base oils resist fuel dilution better than other oils, and their 5w30 is about the thickest 30-weight you can get. So give that one a try.
Or, German Castrol, 0w30 is a heavy 30-weight that may be OK.
From your OUA, the Iron wear rate was 4.6 ppm per thousand miles, and that's pretty high. Fuel dilution thins out the oil, and even the AMSoil SS barely stayed in grade. And I imagine the solvent effect of the fuel messes with anti-wear additives. At 4600 miles, you seem to have your limit for OCI based on the oil thinning out of grade.
Or maybe you could go to a thin 40, such as Mobil 1 0w40 FS. It is right on the low limit of 40, and I guarantee is will be a 30 weight before 1000 miles. And its 0W-ness will give you good cold flow to keep the cam phasers happy.