knocks and pings

At start up your oil has flowed back to the pan so any bearing wear is most evident then when they are dry. It may be a bad rod of piston bearing. Try disconnecting the coil to one spark plug at a time while running the engine and see if the knock goes away, if it does, then that particular cylinder is the one knocking. I'm assuming that the sound is as you describe a "knock" and not a "tick," which is more of an indication of lifter wear. If the engine has high mileage, try running seafoam for about 100 easy miles to degunk it, then doing an oil change and running high-mileage oil. Dodge motors seem to have the notoriety of poor oil pressure especially at startup.