I have a 2004 f250 6.0 diesel I tride 3 used turbos and they all burnt up and I checked the oil it has good oil pressure they all made strang sounds on start up was it just bad turbos or what ?

Install a new Motorcraft turbo and only use full synthetic heavy duty diesel engine oil; e.g, Mobil 1 or Amsoil. Turbos are like small jet engines and every commercial and military jet in the world only uses full synthetic engine oil. If you don't use full synthetic diesel engine oil, the turbo will not go the distance and it's just a matter of time until it fails.