F30POST
F30POST
2012-2015 BMW 3-Series and 4-Series Forum
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read
BMW 3-Series and 4-Series Forum (F30 / F32) | F30POST > Technical Forums > N55 Turbo Engine / Drivetrain / Exhaust Modifications > Partial load vibration/Stumbling (N55-EWG-Bootmod3 stage1/91)
GetBMWParts
Post Reply
 
Thread Tools Search this Thread
      11-28-2020, 04:12 AM   #23
Wiz992
Private
Oman
5
Rep
50
Posts

Drives: F33/15
Join Date: Jun 2019
Location: MCT

iTrader: (0)

Quote:
Originally Posted by akgambino View Post
What spark plug gap? I see u have relatively new oem plugs, maybe try the colder ngk plugs and gap properly?
Umm, i don't really think it's related to BOSCH plugs and gap cuz the car was running smooth as silk for a long time on stock plugs and they never had any misfires even before replacing them and they were pretty in good shape. I heard many has experienced early misfires on NGK plugs for N55 engines so that's why i went for BOSCH. My brother is running stage 2 for almost 2+ years on BOSCH plugs with no issues at all (Aggressive drivability).

So today, I'll lift the car and examine the Engine mounts, center bearing and Flex disk. Because i started to think that, These parts would be the first to show their defects on high stress/load on low RPM.

Techron (Still in progress)
Cleaning intake manifold (Soon)

Will update later !
Cheers!
Appreciate 0
      11-29-2020, 11:26 AM   #24
Wiz992
Private
Oman
5
Rep
50
Posts

Drives: F33/15
Join Date: Jun 2019
Location: MCT

iTrader: (0)

Update after Mechanical check

Hi guys !

So The car was lifted and the below parts were checked and tested:

-Flex disk
-Shaft center support bearing
-Shaft alignment
-Engine and transmission mounts
-Deferential
-Suspension
All the above parts were in good conditions with no issues at all and the vibration is still persistent under the seat (shaft zone) on OTS maps (Feels the the gear selection on Auto against torque request is not right and load is too high on 5th,6th&7th).

Last thing left for me is (Cleaning the intake manifold).

Any thoughts ?
Cheers
Appreciate 0
      12-02-2020, 11:30 AM   #25
Wiz992
Private
Oman
5
Rep
50
Posts

Drives: F33/15
Join Date: Jun 2019
Location: MCT

iTrader: (0)

Doubt on 8-Speeds Gear shifting while cruising

For guys who have 8-speeds gear, does your auto gear shifts while cruising close to the below :

5th gear: 25 mph
6th gear: 31 mph
7th gear: 40 mph
8th gear: 53 mph

Thanks
Appreciate 0
      12-02-2020, 01:12 PM   #26
thejeremyman9
Brigadier General
thejeremyman9's Avatar
1627
Rep
3,168
Posts

Drives: 2015 BMW 335i
Join Date: May 2019
Location: Cali

iTrader: (0)

Your shift points seem about right for a 8AT car driving at light throttle on level ground.
Appreciate 0
      12-03-2020, 11:24 AM   #27
Wiz992
Private
Oman
5
Rep
50
Posts

Drives: F33/15
Join Date: Jun 2019
Location: MCT

iTrader: (0)

Quote:
Originally Posted by thejeremyman9 View Post
Your shift points seem about right for a 8AT car driving at light throttle on level ground.
Oh okay. Anyhow, PFS has reduced the torque request on the mentioned RPM and it made a huge improvement (75%) and it still going on. I think it's best to go with XHP flashtool to calibrate the torque limits and shift points to my liking.
Appreciate 0
      12-03-2020, 12:12 PM   #28
thejeremyman9
Brigadier General
thejeremyman9's Avatar
1627
Rep
3,168
Posts

Drives: 2015 BMW 335i
Join Date: May 2019
Location: Cali

iTrader: (0)

Quote:
Originally Posted by Wiz992 View Post
Oh okay. Anyhow, PFS has reduced the torque request on the mentioned RPM and it made a huge improvement (75%) and it still going on. I think it's best to go with XHP flashtool to calibrate the torque limits and shift points to my liking.
Are you currently running BM3 trans flash?
Appreciate 0
      12-03-2020, 05:28 PM   #29
Wiz992
Private
Oman
5
Rep
50
Posts

Drives: F33/15
Join Date: Jun 2019
Location: MCT

iTrader: (0)

Quote:
Originally Posted by thejeremyman9 View Post
Are you currently running BM3 trans flash?
Nope, tried it for a while and it wasn't that smooth at cruising speeds so reverted to stock. Iíll check through ISTA if the thereís any registered TCM codes or bad communication with DME.
Appreciate 0
      12-08-2020, 11:53 AM   #30
Wiz992
Private
Oman
5
Rep
50
Posts

Drives: F33/15
Join Date: Jun 2019
Location: MCT

iTrader: (0)

Gear box adaption values - ZF 8AT

Hi guys !

What do you think of these adaption values ?

https://ibb.co/9g0P5DS
Appreciate 0
      12-08-2020, 12:07 PM   #31
thejeremyman9
Brigadier General
thejeremyman9's Avatar
1627
Rep
3,168
Posts

Drives: 2015 BMW 335i
Join Date: May 2019
Location: Cali

iTrader: (0)

Quote:
Originally Posted by Wiz992 View Post
Hi guys !

What do you think of these adaption values ?

https://ibb.co/9g0P5DS
People rarely post these. Your best bet is to try and google and find other examples. Having said that, everything i have seen says to never reset transmission adaptations.
Appreciate 0
      12-08-2020, 12:57 PM   #32
Wiz992
Private
Oman
5
Rep
50
Posts

Drives: F33/15
Join Date: Jun 2019
Location: MCT

iTrader: (0)

Quote:
Originally Posted by thejeremyman9 View Post
People rarely post these. Your best bet is to try and google and find other examples. Having said that, everything i have seen says to never reset transmission adaptations.
Tried to but it's totally different with everyone on the same gearbox. Agreed, resetting the adaption values without the required relearn procedure might cause bad shifting and related gearbox issues. still, some experienced bad shifting even after doing it properly. Specially with tuned cars. As per XHP " -+400 mbar for pressure adaption and -+40 mbar for quickcharge time are common Max/Min values but still treated as out of tolerance and still can shift normally. Even with +700 mbar as well". So, I was hoping for any tranny experts to point to any off readings if any that may be caused by bad pressure regulator, soelnoids, clutch and etc.

The vibration at low RPM is a nightmare for N55/N54
Appreciate 0
      12-08-2020, 03:06 PM   #33
XutvJet
Brigadier General
3242
Rep
4,021
Posts

Drives: 2016 M235 6MT
Join Date: Mar 2016
Location: Kansas City

iTrader: (-1)

Quote:
Originally Posted by Wiz992 View Post
This only happens only high boost/Low RPM (below 3K) specially on high gears (5,6&7).
This is your answer. It's a high load/low rpm situation created by tunes and piggybacks. They command more boost at lower rpms which puts more load on motor than stock. What you are feeling are harmonic vibrations of the motor under stress, basically the same sensation as lugging the engine in a tall gear.

My M235 didn't do this until I added a Dinan Sport and then more recently with the Dinantronics Stage II piggyback. My friend has noted the same with his Cobb tuned 2011 335i (N55) and his MHD tuned 2015 X1 (N55).

Is detrimental to the motor? Not really unless you're going heavy throttle in a tall gear and at a low rpm. Also, some people, like you and myself, are way more keyed into changes in NVH, throttle response, etc. than others.

You're going to waste a lot of time, money, and mental energy chasing this problem that only has two solutions:

1) Remove the tune
2) Shift to a lower gear and take some load off the motor
__________________
The forest was shrinking, but the Trees kept voting for the Axe, for the Axe was clever and convinced the Trees that because his handle was made of wood, he was one of them.
Appreciate 1
      12-09-2020, 06:12 AM   #34
Wiz992
Private
Oman
5
Rep
50
Posts

Drives: F33/15
Join Date: Jun 2019
Location: MCT

iTrader: (0)

Quote:
Originally Posted by XutvJet View Post
This is your answer. It's a high load/low rpm situation created by tunes and piggybacks. They command more boost at lower rpms which puts more load on motor than stock. What you are feeling are harmonic vibrations of the motor under stress, basically the same sensation as lugging the engine in a tall gear.

My M235 didn't do this until I added a Dinan Sport and then more recently with the Dinantronics Stage II piggyback. My friend has noted the same with his Cobb tuned 2011 335i (N55) and his MHD tuned 2015 X1 (N55).

Is detrimental to the motor? Not really unless you're going heavy throttle in a tall gear and at a low rpm. Also, some people, like you and myself, are way more keyed into changes in NVH, throttle response, etc. than others.

You're going to waste a lot of time, money, and mental energy chasing this problem that only has two solutions:

1) Remove the tune
2) Shift to a lower gear and take some load off the motor

I kept mulling this possibility but some part of me was thinking that, it might be due to inconsistent tune/ faulty parts and etc.. But now after a
lot tests and replacements , I realized that, the high stress on high gears/Low RPM can only be controlled either by removing the tune as you said or reducing the torque request on low RPM or by calibrating the shift speed on each gear without reducing the torque limits which is what I'm planning to do.
Appreciate 0
      12-09-2020, 12:43 PM   #35
XutvJet
Brigadier General
3242
Rep
4,021
Posts

Drives: 2016 M235 6MT
Join Date: Mar 2016
Location: Kansas City

iTrader: (-1)

When you get the vibration, are you manually holding the gear or are you in automatic? Usually automatics are pretty quick to downshift when they sense this situation.

Luckily the DME on these cars is very smart and quick to react in these high load situations to keep from damaging the motor. In cars like my old 2012 WRX, if you were to lug the motor in a high gear with a tune, you seriously risk creating super knock event and spinning a rod bearing or breaking a ringland. In the 2015+ WRXs with direct injection and other DI turbo cars, it can cause Low Speed Pre-ignition (LSPI). Late model turbo BMWs don't seem to have much issue with LSPI.

Turbos are load dependent. Put more load against them and the faster and harder they'll spool. It's why not much boost is generated in the lower gears vs the taller gears and also why some poorly tuned cars can have boost run away under high load/low rpm situations.

Overall, there are so many damn sensors on these motors that the DME can usually pick up an issue and throw some sort of code, thus I would think you're N55 would be telling you there's an issue or you could obviously see it with datalogging. Also, people can read WAY too much into datalogging, especially part throttle datalogging. Part throttle datalogging is very problematic because of a very high variability in tuning strategies in those situations. Boost, AFR, timing, and even knock can be all over the place and it doesn't mean there's a problem.
__________________
The forest was shrinking, but the Trees kept voting for the Axe, for the Axe was clever and convinced the Trees that because his handle was made of wood, he was one of them.
Appreciate 0
      12-09-2020, 01:52 PM   #36
Wiz992
Private
Oman
5
Rep
50
Posts

Drives: F33/15
Join Date: Jun 2019
Location: MCT

iTrader: (0)

Quote:
Originally Posted by XutvJet View Post
When you get the vibration, are you manually holding the gear or are you in automatic? Usually automatics are pretty quick to downshift when they sense this situation.

Luckily the DME on these cars is very smart and quick to react in these high load situations to keep from damaging the motor. In cars like my old 2012 WRX, if you were to lug the motor in a high gear with a tune, you seriously risk creating super knock event and spinning a rod bearing or breaking a ringland. In the 2015+ WRXs with direct injection and other DI turbo cars, it can cause Low Speed Pre-ignition (LSPI). Late model turbo BMWs don't seem to have much issue with LSPI.

Turbos are load dependent. Put more load against them and the faster and harder they'll spool. It's why not much boost is generated in the lower gears vs the taller gears and also why some poorly tuned cars can have boost run away under high load/low rpm situations.

Overall, there are so many damn sensors on these motors that the DME can usually pick up an issue and throw some sort of code, thus I would think you're N55 would be telling you there's an issue or you could obviously see it with datalogging. Also, people can read WAY too much into datalogging, especially part throttle datalogging. Part throttle datalogging is very problematic because of a very high variability in tuning strategies in those situations. Boost, AFR, timing, and even knock can be all over the place and it doesn't mean there's a problem.
It only happens in Auto mode on high gears (6th,7th & 8th) during partial load and below 3K RPM. Which will produce maximum boost limit of the map without downshifting. The vibration is eliminated during WOT where the gear shifting happens automatically but the shifting response are way better in stock map. As for log readings, they are pretty good.
Yeah man, you really don't want to get into this kind of headache. Just recently, my friend broke his ringland on his STI after he installed the precision turbo. There are no registered codes in ISTA. it only shows in current faults that, the car has experienced a jerking/power loss during partial load. See the below link.

https://ibb.co/HYWfPTT
Appreciate 0
      12-10-2020, 12:58 PM   #37
Wiz992
Private
Oman
5
Rep
50
Posts

Drives: F33/15
Join Date: Jun 2019
Location: MCT

iTrader: (0)

Update: after reducing the torque request

Hi guys !

So after reducing the torque request below 3K RPM, the vibration disappeared completely and the car runs perfectly smooth. So for guys who encounter similar issue in the future with the symptoms mentioned in this thread, you may want to add this in your checklist.

Awaiting the ethernet adapter so i can start calibrating the shift speeds without altering the torque request.

Will update later.
Appreciate 0
      12-19-2020, 12:12 PM   #38
Rolynyari620
Private
6
Rep
77
Posts

Drives: 335I N55
Join Date: Apr 2013
Location: Central Florida

iTrader: (1)

Quote:
Originally Posted by Wiz992 View Post
Hi guys !

So after reducing the torque request below 3K RPM, the vibration disappeared completely and the car runs perfectly smooth. So for guys who encounter similar issue in the future with the symptoms mentioned in this thread, you may want to add this in your checklist.

Awaiting the ethernet adapter so i can start calibrating the shift speeds without altering the torque request.

Will update later.
I think I just started having the same problem with my N55 EWG yesterday. I've been running Bootmod3 Stage 1 93 OCT fine and it has been super smooth. Yesterday suddenly it started creating a weird jerk at about 50% throttle in the lower RPM range. How did you fix it again? I'm pretty new to Tuning on bootmod3. Thank you!
Appreciate 0
      12-20-2020, 02:17 PM   #39
Wiz992
Private
Oman
5
Rep
50
Posts

Drives: F33/15
Join Date: Jun 2019
Location: MCT

iTrader: (0)

Quote:
Originally Posted by Rolynyari620 View Post
I think I just started having the same problem with my N55 EWG yesterday. I've been running Bootmod3 Stage 1 93 OCT fine and it has been super smooth. Yesterday suddenly it started creating a weird jerk at about 50% throttle in the lower RPM range. How did you fix it again? I'm pretty new to Tuning on bootmod3. Thank you!
Hi Rolynyari620 !

First step you need to check the below:
- CP in case of recent replacement (Loose clamps, fittings, cleaned MAP sensor & incorrect location of O-ring) or cracked OEM CP.
-In case of recent replacement of DP (Check the DP clamps and O2 sensors shall be well connected and on the right ports)
- Check through BM3 app if there are any engine codes (Misfires, O2 sensors codes & etc..)
- Log during WOT and partial throttle on the speed of vibration and share them.

Where does the vibration originates from ?
Let me know if any changes has been made during the last two weeks.
We also need to know your mods and mileage.

If the above is all good, you might need to reduce the torque request or adjust the shift points and speeds.

Last edited by Wiz992; 12-20-2020 at 02:29 PM.. Reason: We also need to know your mods and mileage
Appreciate 1
      12-20-2020, 03:12 PM   #40
Rolynyari620
Private
6
Rep
77
Posts

Drives: 335I N55
Join Date: Apr 2013
Location: Central Florida

iTrader: (1)

Quote:
Originally Posted by Wiz992 View Post
Hi Rolynyari620 !

First step you need to check the below:
- CP in case of recent replacement (Loose clamps, fittings, cleaned MAP sensor & incorrect location of O-ring) or cracked OEM CP.
-In case of recent replacement of DP (Check the DP clamps and O2 sensors shall be well connected and on the right ports)
- Check through BM3 app if there are any engine codes (Misfires, O2 sensors codes & etc..)
- Log during WOT and partial throttle on the speed of vibration and share them.

Where does the vibration originates from ?
Let me know if any changes has been made during the last two weeks.
We also need to know your mods and mileage.

If the above is all good, you might need to reduce the torque request or adjust the shift points and speeds.
Hi Wiz992!
Thank you so much for chimming in, I definitely appreciate it!
So I just flashed back to Stock Flash and took her for a spin. Perfectly normal. I forgot how tame she was
As far as drive train mods, I'm running ER CP, Turner open carbon intake and Megan Supremo exhaust. 52K miles on the clock. All maintenance up to date by my Euro shop. Spark plugs and coils are maybe 4k miles old. Liquimoly oil. She's normally very good to me. She's clocked at 4.2 0-60 using my P3 vent gauge.
The only thing I did right before this issue was change burble settings and refill gas using a gas station that I don't normally go to.
I probably should not have increased my burble length and aggressiveness as much as I did with a stock DP. I went pretty aggressive.
I was thinking of maybe running through this whole tank of gas while staying on the stock flash and then flashing back once I refill with my normal 93oct?

Does that make sense or might it be useless?
Appreciate 0
      12-20-2020, 03:36 PM   #41
thejeremyman9
Brigadier General
thejeremyman9's Avatar
1627
Rep
3,168
Posts

Drives: 2015 BMW 335i
Join Date: May 2019
Location: Cali

iTrader: (0)

Quote:
Originally Posted by Rolynyari620 View Post
Hi Wiz992!
Thank you so much for chimming in, I definitely appreciate it!
So I just flashed back to Stock Flash and took her for a spin. Perfectly normal. I forgot how tame she was
As far as drive train mods, I'm running ER CP, Turner open carbon intake and Megan Supremo exhaust. 52K miles on the clock. All maintenance up to date by my Euro shop. Spark plugs and coils are maybe 4k miles old. Liquimoly oil. She's normally very good to me. She's clocked at 4.2 0-60 using my P3 vent gauge.
The only thing I did right before this issue was change burble settings and refill gas using a gas station that I don't normally go to.
I probably should not have increased my burble length and aggressiveness as much as I did with a stock DP. I went pretty aggressive.
I was thinking of maybe running through this whole tank of gas while staying on the stock flash and then flashing back once I refill with my normal 93oct?

Does that make sense or might it be useless?
Collect a couple of logs, WOT in particular, to see if gas quality might be a factor. https://f30.bimmerpost.com/forums/sh....php?t=1732327
Appreciate 0
      12-20-2020, 06:10 PM   #42
Rolynyari620
Private
6
Rep
77
Posts

Drives: 335I N55
Join Date: Apr 2013
Location: Central Florida

iTrader: (1)

Quote:
Originally Posted by thejeremyman9 View Post
Quote:
Originally Posted by Rolynyari620 View Post
Hi Wiz992!
Thank you so much for chimming in, I definitely appreciate it!
So I just flashed back to Stock Flash and took her for a spin. Perfectly normal. I forgot how tame she was
As far as drive train mods, I'm running ER CP, Turner open carbon intake and Megan Supremo exhaust. 52K miles on the clock. All maintenance up to date by my Euro shop. Spark plugs and coils are maybe 4k miles old. Liquimoly oil. She's normally very good to me. She's clocked at 4.2 0-60 using my P3 vent gauge.
The only thing I did right before this issue was change burble settings and refill gas using a gas station that I don't normally go to.
I probably should not have increased my burble length and aggressiveness as much as I did with a stock DP. I went pretty aggressive.
I was thinking of maybe running through this whole tank of gas while staying on the stock flash and then flashing back once I refill with my normal 93oct?

Does that make sense or might it be useless?
Collect a couple of logs, WOT in particular, to see if gas quality might be a factor. https://f30.bimmerpost.com/forums/sh....php?t=1732327
Logs while on stock flash or flash back to Stage 1 93 oct?
Appreciate 0
      12-21-2020, 12:28 PM   #43
thejeremyman9
Brigadier General
thejeremyman9's Avatar
1627
Rep
3,168
Posts

Drives: 2015 BMW 335i
Join Date: May 2019
Location: Cali

iTrader: (0)

Quote:
Originally Posted by Rolynyari620 View Post
Logs while on stock flash or flash back to Stage 1 93 oct?
Stage 1 93 or whatever tune was giving you the issue. If you are still on stock flash, you could grab a log with that too just for a basline/comparison.
Appreciate 0
      12-21-2020, 12:37 PM   #44
Wiz992
Private
Oman
5
Rep
50
Posts

Drives: F33/15
Join Date: Jun 2019
Location: MCT

iTrader: (0)

Quote:
Originally Posted by Rolynyari620 View Post
Logs while on stock flash or flash back to Stage 1 93 oct?
Log on both maps (partial throttle and WOT). Try to create vibrations for the longest possible period while taking logs on partial throttle .

Just to be clear, did you pump your car with less than 93 Oct ?
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 07:31 AM.




f30post
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST