Bump.......still looking for ideas

 

I'm having a hard time believing it's engine oil. Just because it's dark doesn't mean it's not ATF.

Start by checking the transmission fluid and transfer case fluid levels because something is definitely up. The bone dry 3 prong vacuum harness plug is interesting, but I guess stranger things have happened...

Remove your battery and battery tray and locate the 4x4 actuator to see if that has fluid in it as well.

 

I agree with what you are saying 100 percent. I have a new actuator and cable ready to go when I go thru the front end rebuild, (suspension, rad, fan, clutch, pump and so on). Until then I think I will replace the PCV valve and connecting hoses but leave the 4WD plugged. I replaced all that about 2 months ago and everything up to the check valve is soft and loose already. I wonder if the rings @ 130K could be so bad that crankcase vapors (blow-by) are working their way back up to the check valve and leaving a bit of oil in the hoses......yes I know I'm grasping at straws.

 

Since you're going to be replacing things, you might as well get a new transfer case vacuum switch (AC Delco p/n 89059420) too.

I went through and did all the 5/32 line and 7/32 line as well as the reservoir and check valve. I was only getting air out of the defrost and feet so I did the HVAC actuators as well. I still have no idea what the issue was because all 3 held vacuum, but the colored lines could have just been clogged/ gummed up too. I flushed them with a mild degreaser.

 

New vacuum lines and switch are on the very long list of things that need to happen.