gauge shows oil pressure dropping

Have you checked the oil level?

also change the sending unit...cant hurt..

Oil level is good, changed it yesterday to make sure nothing metallic in it. Have used Mobil 1 for a couple of years. Changed sending unit last night. Still had the same problem today. Let it run about a minute with bells going off with the hood up, no noise at all. Turn it off and start it right back up with 40 lbs at idle. Called dealer, gave them the vin and they said no filter screen under sending unit for this model.

Ya the screen I believe they started in 2006. No noises is a good sign, but I guess I would get a mechanical gauge and screw in there and actually check the oil pressure to be sure there is a problem.

Ah, I remember hearing something on these years, is that the 5.3L?

Yes 5.3L. Wondering about the bypass in the oil pump. It idled this morning for 45 minutes and stayed around 40lbs at idle(38 - 40) the whole time. and after driving for 25 minutes pressure started dropping. But like I said. Turned it off and started right back up to 40 lbs.

Ya that is one thing I have heard on those. Since it is predictable, I would throw a oil pressure gauge on it to verify.

check oil pressure sensor, maybe have a friend move the plug and see if you get different readings. you can take out and clean, most of the time if you have it out just replace lol but hey not everyone has doe to throw around. i know they have problems with the dash clusters giving bad readings and they need repaired. guys on ebay repair them pretty cheap.