[dbrizz]

I'm joining the limp mode party. 2008 BMW 335xi 98,000 miles. Took my car to Grattan raceway (MI) this past weekend (my first track day ever). Before I went to the track, I replaced breaks, break fluid, walnut blasting. No engine lights whatsoever. Not even when driving really hard on the street. Show up at Grattan and I'm with an instructor for the first couple of laps so I wasn't pushing it hard and made it to the checkered flag (20 minutes). Second time out an instructor is with me again, I start feeling more confident and start pushing it harder, about 10 minutes in, I'm coming up a hill and got the pedal down in 3rd gear heading towards the straight, shift into 4th gear, about 2 seconds later boom limp mode. I get off the track, turn it off and turn it back on, the error is gone. I pull the codes, and guess what? No codes. Check all service levels, oil looks good, temp looks good. I Google it and disable traction control completely (hold 3 seconds). So we eat lunch, I let the car cool off and go back out for the third session with traction control completely off, second lap in limp mode. #$## Raging now. Get off the track, pull code while light is still on, no codes (I'm using a cheap scanner OBDII scanner, not the expensive BMW ones). Turn it off, turn it back on no light / code, go back on track WITH traction control fully back on (normal) and the third lap this time I go into limp mode. Get really pissed, pull off and shut my car down for the day. Hang out for a while, talk to some BMW dudes who all tried pulling codes and couldn't find anything. So I drive home and no lights so far, I say what the hell let me see if I can recreate this... doing about 40 mph in 3rd gear down a back road, nail it up to 70 and boom limp mode. @$@#@! Pull over, turn it off and turn it back on. Drive home at 50mph in 4th gear and never popped up again. So my car sits in my garage for 2 days then, I jump back in it and drive somewhere for work, I let it get up to temp 245ish, then jump on it because why not? This time no lights and I can shift cleanly all the way up to 6th without issue. Limp mode happened on Sunday and it's now Thursday. I haven't gotten one limp mode since Sunday. Oh by the way my oil temps only went slightly higher than normal. When my car is warm it’s around 240-250. At the track it was barely over 250.

My car is stock besides 18” VMR 710 wheels. No modifications whatsoever to cooling or engine or suspension.

So here’s my dilemma, I want to track more and after reading everything in this thread I’m not entirely sure this is the car I can beat on for 1-2 straight at track. For the guys who have had a tons of limp modes similar to the above, how did you remedy this and start getting through ATLEAST a day at the track? I’m only talking about 3-5 20 minute sessions in 80-90 degree weather. Will a aftermarket oil cooler, radiator, etc really make a difference? I wanted to get some KW V1s but I'm not doing that now until I know this thing can handle at least a moderate track day.