Hello, I'm Danny.
Just be sure to use the correct viscosity motor oil that your truck calls for. When your truck is cold and you are using a heavier weight motor oil it is the thickest when cold. After your engine warms up the oil will thin out and flow better throughout the engine. The correct oil to use will be marked on the oil fill cap. Since you didn't specify which V6 your truck has the 3.0 L uses 5W-20 oil, And the 4.0L uses 5W-30 oil.
This guide can help as well, and I have included the oil sending unit so you can check the connection or replace the sensor.
https://www.2carpros.com/articles/high-or-low-engine-oil-pressure
Check out the diagrams (Below). Please let us know what happens. Hope this helps and thanks for using 2CarPros.
Images (Click to enlarge)
Dec 7, 2020 at 8:28 AM
(Merged)