[Chrisguilday]

Hey guys, I have a 2011 E93 335i with 132K miles.

My car is FBO MHD stage 2+

When driving in normal automatic mode the car shifts normal, however if I put it in sport mode and shift it manually it acts very weird most of the time, but sometimes it doesn’t. I’m not sure exactly how auto trans works, but the best way I can describe it is if the trans is not pushing the (clutch plates?) together firm enough. Or like it doesn’t have enough pressure. I’ll try to explain the best I can below:

In sport manual mode If I floor it and up-shift and continue flooring it’s “typically” fine, but if I floor it, up shift, and then LET OFF the throttle after shifting it will almost feel like it’s not engaging the next gear properly, like there’s not enough pressure to firmly shift into the next gear. In non-sport mode but still shifting manually it doesn’t really do this, or at least not as bad. However one time I put the MHD trans tune on it and it made this issue so bad it was undrivable. After shifting it would often kick the gear back out and downshift back to the prior gear, and then it would flash a trans code. However if I continued to keep holding down the gas after shifting it wouldn’t do this.

Another thing it does is when shifting it seems like the trans is not shifting fast enough compared to what the engine thinks, and it will cause the revs to blip up in-between shifts. However I haven’t ever felt a “slipping” feeling in the trans, it only ever has issues while shifting.

So anyway, does this problem sound like it could be the transmission solenoids or the valve body sleeves? I don’t know much about either, but if it’s repairable and runs me $300 ish in parts I can likely do it myself, but if not a 2nd hand trans is like $700.