Idle oscillations...Lets solve it together!

BIMMEROV · 06-04-2021, 07:44 PM

Hi,
So as the title states Im having idle oscillations on my 11 535i xdrive. I was running BM3 stage 2 93 oct OTS tune which amplified the issue to a point where at idle speeds in gear (foot off the gas pedal) the car would jerk back n forth. Thinking there is problem with the tune, I detuned it back to stock and the issue is still present but a lot less violent. Did some maintenance like plugs and coils, cleaned the MAF still no result. So Im kinda running out of ideas and figured I'd ask the experts...
Current mods are:
VRSF catless dp
BMS charge pipe
BMS intake

Recent maintenance:
NGK oem replacemnt plugs
Eldor coilpacks
HPFP was done at the dealership couple of years ago.

Here are some data logs ive done via BM3 app.

Stage 2 93 octane tune idle
https://www.bootmod3.net/log?id=60b1...729b37e9a80a62

Stage 2 93 octane tune 3rd gear pull
https://www.bootmod3.net/log?id=60b2...0b432b33dcefa2

Stock tune idle
https://www.bootmod3.net/log?id=60b6...90c6105d4767a5

Stock tune 3rd gear pull
https://www.bootmod3.net/log?id=60b6...0b436b0461ade1

Any input would be appreciate it..

David_Vasha · 07-11-2021, 01:25 AM

Myself and multiple other drivers of the Pre LCI version with the N55 motor have been dealing with this issue. I've posted a couple times trying to see what it could possibly be but to now avail. I have the same exact situation as yours and it's driving me crazy. After doing extensive research (at least on the healthiness of my cars engine) I'm leaning towards it being a software/firmware update being needed.

MatthewLC · 07-12-2021, 09:53 PM

I also have the same issue that I've been trying to resolve, I think it's related to the 2011 N55's. From what I've been able to gather through research it's a common issue with E90 N55's which is basically the same engine/dme in the 2011 535. A lot of the E90 guys complain that these weird idle oscillations occurred after installing a catless downpipe.

I have basically the same mods as OP: BM3 tune, VRSF downpipe and VRSF charge pipe.

I'm curious if those with a MHD tune have the same issue? That might be able to give some insight on it being a software/firmware issue?

For context I've replaced similar items:
- NGK One step colder plugs
- Eldor Coils
- New Injectors

Smoke tested the car, found some vacuum leaks, resolved those but it didn't make a difference on idle. Car seems to run perfect other than idle. For me it seems like more of a misfire rather than an oscillation. I'm am experiencing the same timing swings at idle which seems to be causing the issue.

BIMMEROV · 07-17-2021, 12:15 PM

Yeah the more I research it definitely seems like a software issue.
Mine also feels like a misfire at times like MatthewLC mentioned. I was going to replace my injectors but it seems like it didnt help you guys so Im going to wait on that. Some people tried replacing their O2 sensors which had no effect either.

Im kinda wondering if the secondary O2 sensor has anything to do with this? Supposedly the tune shuts it off but computers in these cars are pretty particular with system integrity.

David_Vasha · 07-22-2021, 11:58 AM

I'm thinking that it really just comes down to the DME software that these cars come with from 2011 or 2010. I haven't done this yet but I think updating my modules to all the up to date software will solve my issue. If not then it was for peace of mind and now I know it's wasn't a software issue.

06-04-2021, 07:44 PM	#1
BIMMEROV Registered 0 Rep 4 Posts Drives: 2011 535xdrive M sport Join Date: Aug 2017 Location: IL iTrader: (0)	Idle oscillations...Lets solve it together! Hi, So as the title states Im having idle oscillations on my 11 535i xdrive. I was running BM3 stage 2 93 oct OTS tune which amplified the issue to a point where at idle speeds in gear (foot off the gas pedal) the car would jerk back n forth. Thinking there is problem with the tune, I detuned it back to stock and the issue is still present but a lot less violent. Did some maintenance like plugs and coils, cleaned the MAF still no result. So Im kinda running out of ideas and figured I'd ask the experts... Current mods are: VRSF catless dp BMS charge pipe BMS intake Recent maintenance: NGK oem replacemnt plugs Eldor coilpacks HPFP was done at the dealership couple of years ago. Here are some data logs ive done via BM3 app. Stage 2 93 octane tune idle https://www.bootmod3.net/log?id=60b1...729b37e9a80a62 Stage 2 93 octane tune 3rd gear pull https://www.bootmod3.net/log?id=60b2...0b432b33dcefa2 Stock tune idle https://www.bootmod3.net/log?id=60b6...90c6105d4767a5 Stock tune 3rd gear pull https://www.bootmod3.net/log?id=60b6...0b436b0461ade1 Any input would be appreciate it..
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07-11-2021, 01:25 AM	#2
David_Vasha Private First Class 35 Rep 199 Posts Drives: 2011 535i XDrive Join Date: Apr 2019 Location: Charlotte, North Carolina iTrader: (0)	Myself and multiple other drivers of the Pre LCI version with the N55 motor have been dealing with this issue. I've posted a couple times trying to see what it could possibly be but to now avail. I have the same exact situation as yours and it's driving me crazy. After doing extensive research (at least on the healthiness of my cars engine) I'm leaning towards it being a software/firmware update being needed.
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07-12-2021, 09:53 PM	#3
MatthewLC Private 23 Rep 53 Posts Drives: 2011 BMW 535i Join Date: Mar 2018 Location: Toronto, Ontario iTrader: (0)	I also have the same issue that I've been trying to resolve, I think it's related to the 2011 N55's. From what I've been able to gather through research it's a common issue with E90 N55's which is basically the same engine/dme in the 2011 535. A lot of the E90 guys complain that these weird idle oscillations occurred after installing a catless downpipe. I have basically the same mods as OP: BM3 tune, VRSF downpipe and VRSF charge pipe. I'm curious if those with a MHD tune have the same issue? That might be able to give some insight on it being a software/firmware issue? For context I've replaced similar items: - NGK One step colder plugs - Eldor Coils - New Injectors Smoke tested the car, found some vacuum leaks, resolved those but it didn't make a difference on idle. Car seems to run perfect other than idle. For me it seems like more of a misfire rather than an oscillation. I'm am experiencing the same timing swings at idle which seems to be causing the issue.
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07-17-2021, 12:15 PM	#4
BIMMEROV Registered 0 Rep 4 Posts Drives: 2011 535xdrive M sport Join Date: Aug 2017 Location: IL iTrader: (0)	Yeah the more I research it definitely seems like a software issue. Mine also feels like a misfire at times like MatthewLC mentioned. I was going to replace my injectors but it seems like it didnt help you guys so Im going to wait on that. Some people tried replacing their O2 sensors which had no effect either. Im kinda wondering if the secondary O2 sensor has anything to do with this? Supposedly the tune shuts it off but computers in these cars are pretty particular with system integrity.
	Appreciate 0 Quote

07-22-2021, 11:58 AM	#5
David_Vasha Private First Class 35 Rep 199 Posts Drives: 2011 535i XDrive Join Date: Apr 2019 Location: Charlotte, North Carolina iTrader: (0)	I'm thinking that it really just comes down to the DME software that these cars come with from 2011 or 2010. I haven't done this yet but I think updating my modules to all the up to date software will solve my issue. If not then it was for peace of mind and now I know it's wasn't a software issue.
	Appreciate 0 Quote