2001 suburban 5.3 can oil pump drain out?

[Wbzautocustomiz]

2001 Suburban 5.3 1500 4WD 225,000 miles so truck sat parked on a small incline nose facing downhill for about 3 weeks then when I started the truck and a real bad knocking sound as if no oil the gauge does show good pressure. Shut it off checked all fluids was good but still a real bad knocking sound shut off til I can find more info. Truck ran fine before I parked it and I am asking is it possible for the oil pump to drain itself from the way it sat? And if it could have is there a way to prime the oil pump back up without a big deal? Or any suggestions where to start?

 

[Maximus1]

More than likely it's a lifter tap instead of a knock. If it wasn't knocking when you parked it, it shouldn't be knocking now. After sitting for so long the hydraulic lifters drained all the oil out of them and it takes a few minutes to get them pumped back up. Just start it and let it idle for a few minutes. As long as you have oil pressure you'll be fine.

 

[Matahoe]

I had a horrible racket from the starter pinion sticking after letting my tahoe sit for two weeks. Old original starter with sticking solenoid or shift fork more than likely.