I finally got the oil line reconnected to the block. I cranked on it a few times to build up oil pressure. It started up and ran well, the oil pressure was good. Drove around the block and it seemed to have a miss. The oil pressure dropped to 40. Once you release the throttle the oil pressure goes down to 20, and of course it feels like it's gonna die. At one point there was a very loud noise that sounded like the squeal from a belt, but I its more like metal-on-metal somewhere in then engine. Is this the oil pump or worse?
1998 K2500 Escalade/Suburban 6.5 TD<br />1997 K3500 Ext.Cab Dually 6.5 TD<br />1983 K2500 Suburban 6.2<br />1983 K1500 Suburban 6.2<br />1983 C1500 Suburban 6.2
I would suggest hooking up a direct reading oil pressure gage. The pressures you're quoting don't sound all that far off, but the noises you're describing sound like ruined main or rod bearings. 
Hope not. 
The mechanical gage will let you know for sure what the oil pressure is. Some folks say the gages in these trucks aren't very good.
