Jeep grand cherokee sounds like the engine is knocking

My 2000 jeep grand cherokee sounds like the engine is knocking, there is no oil presure, and it will not stay running. What do I do?Answer:If you have this many problems with this engine I would suggest getting a used engine with low miles and a warranty you can get one for less than a 1,000 and installed for around 500-600 dollars. Once they begin knocking I don't repair them because you don't