[sjsstl]

I have been at 3 track days with 2 similar G29 30i's and both exhibit SIGNIFICANT power loss regularly during the session. Happens intermittently several times during most sessions including at the beginning so unlikely to be a heat issue and on straights as well as curves. The Sport Display shows the immediate loss of 50% or more power and torque but full power will always return seemingly instantly after 5-20 seconds or so. Shifting down or up does not help. I do not think it is fuel starvation since it happens all around a track and comes and goes nearly immediately.

Thanks in advance for any ideas, I am baffled and doubt a dealer would be of any help with this.

[Amadeo]

Track drove my Z4 30i for one hour, mostly at 120 m/h and got a check engine light because of cathalitic converter malfunction.No power loss, cleared the check engine light and it never happened again . I think these bmw engines are like most german engines, they do very well what they are supposed to do, but, don’t ask them for anything else or they will complain. I don’t know if it’s a myth but here, we believe that German machinery is built so precise, that during Second World War as soon as outside temperatures change fast like during Russian winter, they failed . That’s precision engineering.Not good for wild drivers.

[CJ421]

I think you'd need to collect data (and any codes that are being thrown) to diagnose this properly. Check out the Bimmerlink app.

Charles

[sjsstl]

Just got back from BMW dealer who says no codes or anything obvious but they refuse to diagnose since car is tracked!
Anyone have an idea if a tune might work?