I am hoping to get help diagnosing a current problem I am having with my 2008 335i from someone who may have had a similar issue. I upgraded to this car a few months ago from a e46 323ci so I still have a lot to learn on the e90s. Tonight I was pulling out from a stop sign and the half engine yellow light came on, shortly followed by the upper yellow "check engine soon" light. The radiator fan then started blowing at full speed, but I never smelled coolant. I raised the hood with it running and didn't hear anything abnormal besides the fan. I was a couple miles from home, so I limped it back to get my OBD2 reader. The whole way it was jerking and surging, especially below 2500 RPM. The code reader found 3 codes, but just displayed them as "N/A". I will try to borrow a better reader from a friend, but in the mean time trying to find some answers. I erased the codes and restarted the car and both lights immediately came back on. Any suggestions/advice would be greatly appreciated!