UPDATE.

Had no choice but to drive it to work this morning. Started up fine with no knock and the pressure gauge inside was reading 18 lbs at idle. Started driving and went up to about 40, went to a stop then the gauge went down to 0 and check gauge light came on. I'm going to get an oil change along with filter after work with 10w40, and getting a pressure tester and I'm starting to think the pressure sensor sender is bad. Maybe that knock was just a freak thing. I've only heard it once. If I actually had 0 pressure at idle like it indicates it would be heating up and my lifters would be making a loud racket and they weren't. Sound about right fellas?

 

Might be too late, but, use 5W30 oil, not 10W30. Using thicker oil will increase oil pressure and decrease oil volume, (flow) not a good idea. Always use what the manufacturer recommends. Check the oil pressure when hot, both at idle and at 2K rpm, and let us know what you find