Originally Posted By: TallPaul
2001 Ranger 2.3L, 103,500 miles.
Out: Valvoline Synpower 0w20 after 6500 miles on Wix filter. Was since Nov 2014.
In: Pennzoil Platinum 5w20. Wix filter.
Well, out with the Wix filter. Not sure, maybe was a bad one. But the oil pressure (mechanical gauge) was fluctuating about 8 psi at high frequency, like it had the jitters, any rpm, idle or going down the road under load. I pulled the Wix and spun a Motorcraft FL400s and it seems fine now, but the cold start will really tell because with the Wix it seemed to smooth out some after it warmed up. Still, should not have been that way. Maybe will have to send the Wix in for analysis.