I'm not worried about it since now the oil pressure has pretty much stabilized at 1/4 hot and 1/2 cold, but for the first 100,000 miles I've driven it it always ran at 1/8 hot and 1/4 cold. It use to bother me coming to a stop and watching the gauge bottom out until I accelerated, but I got use to it. I haven't changed oil brands ( Castrol 10W30 ) or filter brands ( Toyota ), but it began to increase slowly over the last 3 months to where it reads now. Just wondering what caused the change on an engine nearing the 300,000 mark. Oil sending unit finally reading right or wrong?, some blockage suddenly disappeared?, The Lubrication Gods have smiled on me?. Any ideas?

 

Gotta be an electrical malfunction.They all have oil pressure hot idling but none ever show any.High or low resistance in the OP sender circuit is probly the culprit.
Bigblock

 

OP sending unit is kinda where I figured the problem was, but it reads where it seems it should now. Maybe I should take an ohm reading and mass produce them so all the 3.0 read more in the normal range. I knew there was pressure back when the gauge dropped to zero by screwing in a mechanical gauge quite a few years back, so I never thought about it until I realized it doesn't drop down that far anymore.

 

ambient temps have dropped, your oil will remain thicker than it normally would in the summer months, mine does the same thing

 

Been rising since july and our warmest month was end of august to beginning of september. Regardless it has been an increase that never happened in the last 8 years. I've never had pressure even at 1/2 on the gauge even in -35 F.

 

well dont jinx a good thing haha