Brought the 99 to the shop for a pick up tube o-ring replacement. Took about 8 hours, and left me wishing all I needed in PA was a 2wd truck.
The factory o-ring was less circular and more tubular than it should’ve been.
Once it was out, it looked like half of it was in contact with the pump for quite a while, long enough to stain the o-ring with oil coloring.
Around the end of November, the oil pressure at cold idle dropped to low to mid 20s from a constant 40 and the engine started running for several seconds in colder weather with 0 oil pressure, and only reached 40 when warm.
8 hours, a bunch of cleaning, cursing, and the occasional drop of oil in the eye, it went together and I saw this on the dash less than 4 seconds after starting it:
50 psi. In an engine that *may* have 300k on it.
I’m overjoyed, too bad the rest of the truck is so bad, I’ll need to replace it this year.