Only after driving long distances the bottom of the vehicle is covered in oil

Okay, check your PCV valve and make sure it is working.

Roy

I don't think there is one on this motor.

It has a PCV system which is a breather. Make sure the hoses and the inside of the air filter assembly are clean of all dirt and debris.

Roy

Positive Crankcase Ventilation Hose/Pipe/Tube Replacement

Removal Procedure

imageOpen In New TabZoom/Print

1. Disconnect the crankcase dirty air hose from the intake manifold.
2. Disconnect the crankcase dirty air hose from the positive crankcase ventilation (PCV) orifice tube.

ImageOpen In New TabZoom/Print

3. Loosen the throttle body clamps (2).
4. Disconnect the fuel pressure regulator vacuum supply hose from the air cleaner outlet resonator.

ImageOpen In New TabZoom/Print

5. Remove the 2 resonator to engine bolts (4) from the air cleaner outlet resonator (5).

ImageOpen In New TabZoom/Print

6. Lift up the front of the air cleaner outlet resonator (2).
7. Disconnect the crankcase clean air hose from the valve cover port.
8. Disconnect the crankcase clean air hose from the air cleaner outlet resonator (2).

I've taken this off and cleaned it and the throttle body before. There is always oil in the resonator. Never oil in the air filter though and the only PCV hose is the little elbow going into the valve cover.

Okay, then back to burning it when you are on the highway. That is the only thing that makes sense.

Roy

It's one way to lose oil but I still have green fluorescence on the frame in the front. These don't have a remote oil filter housing or cooler with a gasket that can fail do they?

No, they do not.

Roy

There remains a bead of oil at the bottom of the oil filter, yet nothing around the base plate shows up. The filter is tight, and I've replaced the sending unit just encase it was leaking but there is not florescent green above the filter.

Got it. I think it's burning it up when you are at high speed.

What weight oil are you using?

Roy

5w-30 synthetic blend, Purolator One oil filters or AC Delco original equipment.

Go to 10 30 and see if it helps.

Roy

So get this; it took this long for the UV dye to show that the oil pressure switch is leaking above the oil filter. I finally saw a bead of oil on it the other day, and when I pulled the connector out of it, the end of the electrical connector was covered in oil.

I had replaced this already. This means the diaphragm blew right? You think this could explain losing 3 quarts of oil on a 700 mile trip up there and 700 miles back?

Yes, it could. Replace it and see what happens.

Roy