No oil pressure at start up, 2001 Tahoe

[grizzlyak]

Usually when the oil pressure sensor fails, it goes all the way to zero, or pegs at max PSI. IMO, fluttering of the oil pressure gauge is either some sort of debris that is impeding the flow of oil from time to time, or it's your oil pressure gauge stepper motor that is on it's way out. Someone who knows more will probably be along shortly to chime in.

Thanks for the info. I was only guessing, but what you say makes sense. In regard to the stepper motor, I'm assuming you are referring to the actual gauge on the dash? If so, is that fairly easy to change? I could probably get a replacement at our local scrap yard who has a good number of 2000-2008 Chevy/GMC 1500 series vehicles.