So I just got the P1624 SES on my 2000 e46. I know this is computer/ engine specific, so I have a 2000 328i M52tub28 engine 5 speed auto/sport :thumbdwn: I believe the date of MFG is around march of 99. I've heard it could be the thermostat with my model and year. I replaced the upper/lower coolant hoses, expansion tank, and I think the thermostat is at the bottom of the expansion tank so that was replaced as well September of 2015 . I did not replace the temp sensor on the lower hose, could that be it? Anyways just wondering if anyone has come up with this issue? Before I leave for work tomorrow I am going to check coolant level, But anything helps!