[Saif2018]

Originally Posted by Derek Keenan

Is everyone experiencing this issue have a 07?

I'm running MSD80 on a 07 335i,

don't have the oscillating issue, maybe it was due to coils or mosfet failing?

[Silent9n54]

Originally Posted by Derek Keenan

I replaced a few things at once but I'm positive upgrading to msd81 fixed my issue, I got rid of my precision raceworks coils and got s55 eldor coils and replaced my valve cover gasket

it could have been your cracked valve cover as well, i have a msd81 on 2010 535xi 6MT and im having the same issue.

[ky0u]

Mine was a combo of blown VC gasket and a leaking injector. Funnily enough, I'm an 07 335i but I don't think my build date was related

[Derek Keenan]

Originally Posted by Derek Keenan

This thread is probably dead now but I ended up fixing the issue

For those who might not know what issue I was having I was having afr spikes in bank 2 only during cruise, afr would be steady around 13-15 while cruising then all of sudden jump from 12 all the way to 17 and back and forth causing a jerking/stutter problem while accelerating from a low rpm. Anytime over 2k rpms it was fine. I replaced 02 sensors but didn't fix. I resealed my injectors and swapped bank1 injectors with bank 2 and recoded them to see if the issue would go to bank 1. The issue completely went away when I took it out to drive, but when I turned it off and then took it back out to drive the problem came back instantly. I took my car in to a local shop and had my injectors tested, injector 6 was dumping more fuel then the rest of the injectors. At the time I thought it could have been my index 1 injectors that I've never replaced but they weren't leaking. I had also swapped injector banks but the problem still occurs in bank 2. Same with coils and plugs, still bank 2. I was told it could have been my ecu but still wasn't sure, when I left the shop I had my cars adaptations reset, and not through MHD, he reset them through his computer on some app, that 40 min drive home it drove home perfect it felt so smooth like it should have. This really boosted my confidence that my ecu might have been the issue. When I got home from the drive I took it back out 2 hours later and it started stuttering instantly. I tested each mosfet for resistance and they were all good. I was about out of options to replace so I went ahead and sent my ecu for msd81 reprogramming and as soon as I got it in the car and drove it, it instantly drove smooth. The guy I sent my ecu too is Omar from vader solutions, luckily i got the last msd81 upgrade they had right now, unfortunately him and I arnt sure who else may have one. Hope this helps

[Derek Keenan]

Originally Posted by ky0u

Mine was a combo of blown VC gasket and a leaking injector. Funnily enough, I'm an 07 335i but I don't think my build date was related

Did you have msd80? I believe all the 07 had msd80 but I'm not %100 sure

[Derek Keenan]

Originally Posted by Saif2018

Also have you done Walnut blasting yet?

No but my valves look pretty rough lol

[Saif2018]

Originally Posted by Derek Keenan

No but my valves look pretty rough lol

lol, good idea to do Walnut blasting

[ky0u]

Originally Posted by Derek Keenan

Did you have msd80? I believe all the 07 had msd80 but I'm not %100 sure

Yes I'm on 80, but haven't had the infamous mosfet issue that effects these (knock on wood)

[Silent9n54]

well i just fixed my hesitation issue, turns out the valves were really diry and walnut blast did the trick. Its butter smooth now

[Saif2018]

Originally Posted by Silent11N54

well i just fixed my hesitation issue, turns out the valves were really diry and walnut blast did the trick. Its butter smooth now

looks a lot cleaner

[Silent9n54]

Originally Posted by Saif2018

looks a lot cleaner

i didnt go crazy on it, it could have come out better than it did but the difference in driveability is night and day.

[iqraceworks]

Can someone explain to me in technical terms why dirty valves would cause that surging issue when cruising at light throttle?

Just trying to make sense of things....

[whyzee125]

Reset all adaptations in INPA. This has fixed it for quite a few including myself.

[Wolf 335]

Originally Posted by iqraceworks

Can someone explain to me in technical terms why dirty valves would cause that surging issue when cruising at light throttle?

Just trying to make sense of things....

Has absolutely nothing to do with walnut blasting or dirty valves.

[iqraceworks]

Originally Posted by Wolf 335

Has absolutely nothing to do with walnut blasting or dirty valves.

That's kind of what I figured. Didn't make any sense to me.

[Saif2018]

Originally Posted by Wolf 335

Has absolutely nothing to do with walnut blasting or dirty valves.

Well the thing is, others have said they walnut blasted and surging/throttle oscillating issue went away,

Carbon build up can cause all sorts of performance issues though,

[Wolf 335]

Originally Posted by Saif2018

Well the thing is, others have said they walnut blasted and surging/throttle oscillating issue went away,

Carbon build up can cause all sorts of performance issues though,

Reason I say it is not related to dirty valves is because guys have reported cleaning valves and not resolving the issue. I also have clean valves and still experiencing the issue.

People that seen improvement after cleaning may have been experiencing a different type of 'hesitation'.

[iqraceworks]

To me sorry valves cause the same result as a dirty air filter......not as much airflow. I've never heard of a dirty air filter causing that type of oscillation at cruising speeds...never, never, ever. And I can't think of a single reason that would logically explain dirty valves causing that type of issue.

Just doesn't make logical sense...

[Chavizard]

I have the same issue when active cruise or when I just put the foot in pedal it make littles shakes.

walnut blasted was done 2000 miles ago so it can not be the car run fine with high revs.

I will try reset adaptations first with mhd but i read it must be with inpa i dont know how do that for now

https://datazap.me/u/xavifdez84hotma...og=2&data=3-22

[Saif2018]

Originally Posted by whyzee125

Reset all adaptations in INPA. This has fixed it for quite a few including myself.

Is there any particular adaptations INPA resets that MHD doesn't?

[whyzee125]

Originally Posted by Saif2018

Is there any particular adaptations INPA resets that MHD doesn't?

No idea. I sent my coder that thread with the BavTechnic one and he reset the same adaptations in INPA. Car is still running perfectly.

[Dave92N54]

Originally Posted by whyzee125

No idea. I sent my coder that thread with the BavTechnic one and he reset the same adaptations in INPA. Car is still running perfectly.

Would you mind posting a link to that thread?

I'm pretty much at a loss to my cause. I've reset all adaptations with MHD and Inpa several times. This morning I cleaned the vanos solenoids and while the car generally feels a lot smoother, especially idle, the issue is still there. Most of the time I can physically see the trims and AFRs just bouncing up and down and not even feel anything (not normal closed loop operation, trims will go all over the place, faster than I can even see but it'd say they jump from -9 to 9). I'm going to order universal secondary 02s and just replace them.

Has anyone here solved this with secondary 02s?