I’ve always run 10w-30 regular ole motor oil on my 99 3.8, someone told me about royal purple so I tried it. Well all was fine except my oil pressure started to dance when I would sit at an idle, especially with the ac running. Now I would assume that it’s due to bad bearings but the pressure dances in unison with my turn signal when I have that thing going so with all that being said I was curious to know where you would want to hook up a separate gage to see what the pressure is really doing? Also while idling if I pull the oil fill cap of I can hear the car bog down as if it was about to die? Any thoughts would be awesome.

 

on the front of the block on the passengers side, below the altenator is your O.P.S.U. Its easy to change it. The only problem is that if you replace it with a mechanical guage, your computer will read no oil pressure, and your SES light will be on. Or, you can get a 1" pc of 1/4" black cast pipe and a T fitting. When you install it, make sure that the T fitting has a opening facing up and one facing out . Run your copper tubing for the mechanical from one inlet on the side and your electrical stock O.P.S.U in the other which will stick straight out.Be sure to use teflon.

 

Right on man that’s what had me messed up, the whole no oil pressure no fuel pressure, safety. I was looking at alldata and they say to use some fitting in place of the oil filter but since I don’t work for the stealership I cant get ahold of them.
Any thoughts on the oil filler cap problem, it kinda fills as if its under vacuum and when I pull it off it loses that vacuum. But should a valve cover be under vacuum?