Quote Originally Posted by JohnH View Post
Hi Nick,

My old 323ci drank like a fish when the thermostat wouldn’t open, and I had the same recently on the m3 when the lambda sensors needed to be changed so I think it could be eitger, or both.

FWIW, I got oem Bosch sensors from Autodoc which were a fraction of the very best Bavarian could do.


just to correct , thermostat opens too early or is not closed properly ,so coolant circulates threw radiator not only in engine and didnt get to the temperatures .if thermostat wouldn't open at all, it would start overheating