I just got finished flushing my cooling system, a seemingly unrelated matter to this and I refilled it with water just to test it out before adding any antifreeze. I started the truck and I happened to notice the oil pressure gauge. It was sort of "wobbling" slightly around 50 pounds. In addition every once in awhile it would bury itself all the way to the left for a few seconds and then come back to normal. I ran it like this for a short time and noticed that it seemed like it would alternate between normal, wobbling, and indicating no oil pressure. If I had to guess it seems like the problem is perhaps electrical in nature because of the speed in which these aberrations take place. Also there is no apparent change in operation, idle speed noise etc during these events. I was wondering if anyone else has seen this before or has any ideas for troubleshooting it. Thanks, Lenny