I don't know a ton about oil pressure and, unfortunately, DanH is not my next door neighbor, so I'm hoping someone can point me in the right direction...
I haven't been flying much over the past 5-6 months but did today and noticed my oil pressure was reading higher (and staying higher) than normal. Though it seems to have been trending slightly or gradually higher the last year or so, today was unusually high.
1. Normally at climb or high cruise power once my oil temp gets up to about 180F I tend to see the oil pressure drop off from the high 80s down into the low 80s, then down to the low 70s at economy 65% cruise. I've generally just guessed this was because the vernatherm opens around 180F and lets oil in the cooler.
2. Normally, once I pull power back (from climb power to 65% power or less I will see a signficant reduction in oil pressure--again, down into the low to mid 70s, or even in 60s if I pull power way back.
However, today, at climb, and high cruise (75%+) power, I was tending to see low 90s psi (yellow range starts at 90psi). Even when my oil temp got up to 185F I was still seeing high 80s psi. Reducing to about 65-70% power only reduced oil pressure into the high 80s, and down to about 45% power it was still mid 80s psi.
0-320-D2A, 600 hours; Kavlico 2-wire pressure sender; Phillips XC20W-50 oil (same as I've always used, year round). No significant engine work in last few hours. OAT=30F. Oil pressure relief valve has been screwed out all the way/nearly all the way ever since it came from Aerosport power so I don't really have any downward adjustment available.
Any suggestions for troubleshooting aside from the "check with another oil pressure gauge"?
Thanks for suggestions on places to start.