Evergreen, CO–temp likely down to freezing overnight
The problem started about 2 weeks ago. I started the truck in the morning, cold and the oil pressure was at 0 and the message light said low oil pressure. After a minute or 2 at idle the message went away and the gauge started to climb. At ~2k rpm the gauge registered in the middle. Several days later the same thing happened only this time the gauge did not budge. I turned off the engine and back on. As soon as the engine turned over the gauge needle would bounce up a bit then return to 0. I had the truck towed to my mechanic. He installed a new gauge. All was fine for about 4-5 days then the same thing happened. As soon as I put the truck in gear and started to back up the gauge came to life and stayed okay. The mechanic said all he could do is put his pressure tester on and test the pressures at various rpm’s per the diagnostic standard. That doesn’t deal with the gauge only having a problem with a cold engine. I asked if there were any other electrical things between the gauge and the pump–no. I asked if there was a tester for an oil pump–no. So that (to me) only leaves the possibility of a flaky oil pump having trouble getting going in cold temps. That would be fine if it were not for the possibility that the pump problem might get worse with time. So that leaves (to me) and the mechanic the only solution being to replace the oil pump just to be sure vs. seizing the engine while driving at some point? Are we missing something?