[GooseMSU]

Hey guys. I have a 2008 BMW 335xi and have been dealing with surging/oscillations for a while now. It only happens at steady throttle. Within the past 40,000 miles I have replaced all injectors to index 12, all 4 oxygen sensors, spark plugs, coils, a couple vacuum lines, throttle body, cleaned intake valves (not walnut blast but still got them a bit cleaner than they were), and some other small things I'm forgetting. Nothing has fixed the issue and periodically I'll just clear adaptations so that it goes away for a couple hundred miles but I know that it will always come back. The only engine code I have that comes up here and there is 29e0 which has to do with fuel air mixture for bank 1. I am still MSD80 and I want to upgrade to MSD81 just to eliminate possible mosfet bugs and I know that the DME very well could be the issue. I'm pretty stumped and don't know if DME is the next thing I want to do. I just took a couple of data logs when the surging was occurring and you can clearly see it when you click on the "RPM" option. They are slight spikes in the graphs but it's pretty noticeable when you feel it. If you guys could take a look at these logs and see if something looks off, I would appreciate it. I wasn't sure what to log so I clicked on whatever I felt was most important but if y'all have any suggestions on which parameters to log, I'd be happy to do it again. All the logs pretty much show the same thing but I just wanted to take a couple at different speeds. Thanks everyone in advance!

https://datazap.me/u/e92n54/log-1?log=0&data=22
https://datazap.me/u/e92n54/log-2?log=0&data=22
https://datazap.me/u/e92n54/log-3?log=0&data=22
https://datazap.me/u/e92n54/log-4?log=0&data=22

[jadams161]

Is the car tuned with MHD? There was an update to the tune and app that has an "oscillation" fix.

[GooseMSU]

I am using MHD and I had just talked to a BMW mechanic who also said that the surging could very well be MHD related but I was not aware of that "oscillation" fix. I will change my settings and make sure to check off that fix. I was also wondering, could the oscillations I am experiencing contribute to the 29e0 (fuel air mixture) code that pops up every so often? I would assume that the oscillations are throwing off my fuel air mixture for split seconds at a time and thought that it might be the cause of that code. I'm just a bit confused because I'm only seeing that code which relates to bank 1. The 29e1 code relates to bank 2 but I never receive that code. Thank you for the help!

[bigsurge]

try setting the mhd wastegate rattle fix to 80% , seems to have worked for me, may still be an underlying issue though

[GooseMSU]

Will give that a shot, thank you!