e92 thermostat

Hello folks! after a little advice again, i was getting the engine management light on the car advising thermostat was stuck open, so i replaced yet yesterday, now the thermostat is not opening and the car is overheating, so i put the old one back on thinking it was a faulty thermostat, not its doing the same thing with the old thermostat that was originally stuck closed!



any ideas on what could be causing this issue? im stumped!