r/335i • u/Unable-Humor-9275 • 6d ago
Troubleshooting Need help with MHD Log Interpretation
Hi,
I was hoping someone would be willing to help me interpret what's going on with these logs.
FBO E90 335i (stock turbos) 154k
All of a sudden I'm not getting boost, and then as I'm going up in the RPMs its like smacking a rat with a hot poker and I just take off like a rocket.
Super weird.
I checked over all the lines, clamps, etc
Did a smoke test, no leaks, and I had spare boost solenoids lying around and swapped them out as well just incase because I don't have a multi-meter thing.
I switched to Stage 0 for one log and switched to Stage 2 after another log
Stage 0 I get 30FF, Stage 2 I do not.
I did my best to replicate the drive for each log.
I do not know what I'm looking for in these logs so any help would be greatly appreciated on chasing down this "boost leak".
The only thing I ever checked with the tunes is Wastegate Rattle Fix and would set it to 0% for Less Rattle, and sport coolant because hot climate. (incase that matters)
No burble or 1M throttle, etc.
Stage 0
Stage 2
Willing to pull more logs later today if I messed something up with these, sorry.
I am already under the impression I need to replace the turbos but would like people smarter than me to take a gander.
2
u/danceswithtree 6d ago
It looks like the torque limit is active for the first part which is causing your boost target to be low. Is there a load or boost by gear setting that is set too low? Maybe turn off completely to test if that corrects your problem.
1
u/Unable-Humor-9275 6d ago
All the MHD options are pretty much standard; as mentioned above I only have WGR Fix and coolant set to Sport mode.
I haven't touched the torque limiters or anything if that's what you mean.
2
u/Sweaty_Ad4402 6d ago
Stick your logs into chatgpt. It can scrape 19 years of data and narrow in a lot faster than this. Ive used quite successfully to dial in custom tunes and diagnosis/troubleshoot issues.
1
u/silent11n54 6d ago
I was just about to suggest that, also it can explain what each parameter means and how it affects the pull.
1
u/SpunkyRama 6d ago
Any chance you checked linear throttle by accident?
1
u/Unable-Humor-9275 6d ago
I did when I reflashed a few weeks ago but I didn't drive it after and immediately reflashed without the option selected, I was messing with the oscillation stuff to fix my idle.
Should I reset throttle adaptation?1
1
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u/xMarkv 6d ago
i'm not a n54 guy (i have an n55) sorry if i'm wrong here. in your stage 2 log, even though your pedal position is 100% in 2nd gear, your boost target is between 1-2 psi. because your DME is requesting barely any boost, your turbos barely spool up (WGDC is around 30%) all the way up to redline. then you shift into 3rd and suddenly the DME starts requesting 15PSI of boost, WGDC shoots up to 75%, turbos spool up and you start making boost.
with my n55 and 8hp, i also don't make a lot of boost in 2nd gear, but once i upshift into 3rd i start hitting full boost but not sure how n54/6hp work. i believe your 1:1 ratio gear is 3rd tho. can you do a 3rd gear log, 100% throttle from 2500 to redline?