My mates got an E46 330 and has recently changed the radiator and although I told him to change the thermostat at the same time, he didn't listen. Hindsights a wonderful thing!
Hes going to change the thermostat this weekend. Is there anything else that should be done while the coolant system has been drained, again? I assume BMW used metal impeller pumps on these M54 engines?
Also he took the car to BMW yesterday and had the codes read off and one of the heaters in the lambdas are faulty. Then when they checked the operation of them they were on constantly even though the engine was up to temp. Do you think a faulty thermostat would cause this?