Had the dreaded oil low pressure warning going up hill, with pressure gauge not passing 60 psi. My fix is volvo FSB 221-011, https://static.nhtsa.gov/odi/tsbs/2013/MC-10126589-9999.pdf The problem is a Pressure Reductions (relief) valve craps out. My dealer had to order the parts at a cost of $79.96. It is on the oil filters housing on the bottom, cover closest to the engine. The SB will guide you in the repair. Simple to the point, 20 mins, 10mm socket, long extension and racket, and rags to clean up spill oil (not alot).
Before the issue, idle just above 30, 1500 rpms between 60 and 90. After the valve failed couldn't pass 60, on hills had to drop a gear or 2 for rpm to run at 1700/1800 to not get the warning and shut off. After the change its better than normal, it's now between 60 and 90 at 1300. Haven't fit the road nor pull any, I'm on home time for two weeks.
