Can anyone help? Cranking not starting X5 e53d

[MStelio]

I’m stumped. Had a few problems with this car, most recently the oil filter housing had corroded, which sent oil everywhere and caused the car to overheat. Managed to get the car home, fixed the problem and flushed everything accordingly, except now it won’t start. Assumed at first it may have been the fuel pump, but checked that and it was fine, so were the relays etc, and it was getting fuel, just won’t kick over. Tried to plug in two seperate OBD2 scanners but just keep getting a ‘link error’. Any ideas or suggestions would be appreciated. It’s a 2003 BMW X5 e53 3.0d.

*Also don’t know if this is significant but once the keys are in and turned, the temperature gauge shoots right up, even though the car hasn’t been started in over a month*