i decided to check thermostat housing ,was losing coolant slowly and wanted to change knock sensor and check for vacuum leaks. when i got the intake off there was oil in the valley , a few ounces, knock sensor was sitting in oil. cant figure where the oil is coming from. any ideas ,thanks and ALOHA

 

Are you sure it is not anti-freeze. When my thermostat housing sprung a leak I found oil like fluid in the 'valley' when I removed the intake. Anti-freeze does not evaporate as quickly as water and will leave an oily like residue. I cleaned it out of there, put on a new thermostat housing and put everything back together. No more fluid in the valley.

 

Thanks for the posts on V6~4.0L~SOHC engines & TStat housings; good reference info.
Replaced the old leaking FRPlastic TStat Housing with a new Aluminum TStat Housing
in 2019Aug on a 2001 Ford ExSportTrac; no leaks as of 2020Mar after ~5K more miles.
My full write up with pics on that repair:
http://2001fordexplorersporttrac.fandom.com/Coolant_ThermoStat_Housing