TJ40ELETB just got this motor. no manual yet. bad me. the fitting is circled in red. the tale tell is purple, and connected to the proper place according to the BRP diagram, down at the bottom. it looks like a second tale tell. but no where to go.
I have seen these before and what I remember is there is a tube that runs to another fitting like the one pictured, I belive it to equlize the pressure. Looking at your pictures it seems the motor has been run with out anything connected . If you have a oil build up around the fitting or where its aimed at then its what I think. If you can turn the motor over see what if anything comes out of the fitting . I cant see the blasted thing in my book but will keep looking.
it's in the water passage cover, no evidence of anything. i guess i'll have to get it mounted and see what comes out. i like the sounds of the water pressure guage. if so i will just block it, for now.