I have a 2006 Ford Mustang 4.0 and a lot of experience with automotive repair. I rebuilt the engine after it overheated and blew the head gaskets, underlying cause was a crack in the radiator. I only did an upper end rebuild mainly replacing gaskets, timing components including timing guide cassettes seemed okay. Cranked up the engine and it rattled like crazy revealing that the timing cassettes were not okay. For the second rebuild I replaced the timing cassettes and head gaskets but did not replace the head bolts. After sitting at idle for about 30 minutes I drove it for half a mile and that's when the oil light first came on. I turned around and tried to make it back home but didn't get far. The engine stalled and I could not get it started again. It was acting like something was resisting it. I dropped the oil pan and found a lot of debris and metal shavings. The third rebuild saw a new crankshaft, new connecting rod bearings, new oil pump, new timing chain tensioners, new head gaskets, new head bolts, new oil and filter, and a thorough disassembly and cleaning of the entire engine. Oil pressure light still comes on after a few seconds of the engine running. The oil pressure sensor has a loose wire in the plug so I was about to check it when the car stalled again. I drained the oil and found more metal shavings. Assuming that I didn't get them all out somehow, I changed the oil and filter again. I cranked it up and the oil pressure light came on then went off. You can imagine the smile on my face. After only a minute the oil pressure light came back on, the engine started running rough then stalled. I tried to start it and it's acting like something is resisting it again. It cranked up once but quickly stalled. I feel like there's no hope and Ford should be punched in the face for designing this motor. Any help with my Mustang would be greatly appreciated