Oil Pressure gauge freaking out

I don't think that the relief spring moves fast enough to make the gauge "flicker".

I could be wrong, but I would lean more toward the drain back valve.

From the research I have been seeing, I agree with the relief spring, where is the drain back valve located? Would another liquid mixed with the oil cause an issue? Water? Gas? I have great oil pressure just very very erratic readings. I wish I could upload the videos I have some how hmm I will try Facebook then here


Would using the priming rod and drill to raise the oil pressure be the same as the car running?