BMW 1 Series Coupe Forum / 1 Series Convertible Forum (1M / tii / 135i / 128i / Coupe / Cabrio / Hatchback) (BMW E82 E88 128i 130i 135i)
 





 

Post Reply
 
Thread Tools Search this Thread
      09-18-2018, 07:21 PM   #23
MattF407
Enlisted Member
United_States
39
Rep
44
Posts

Drives: 2013 Mineral Grey 128i
Join Date: Aug 2016
Location: Tampa, FL

iTrader: (0)

Quote:
Originally Posted by Blutactical View Post
Is the rough idle an issue over time? I was considering a BPC tune but not sure if I should go with AA instead
If you mean, does the idle worsen the longer i drive the car? No, I drive varied commutes & weekend trips and have noticed no correlation between length of time and worsening of idle. I have also never observed correlations between spirited driving or running the AC and a worsening of idle either.

In my case, I do not believe that this is 100% tune related yet. If I do manage to resolve it, I will report back with my findings.
Appreciate 1
      09-18-2018, 08:53 PM   #24
rowsdower
Captain
rowsdower's Avatar
641
Rep
695
Posts

Drives: 2011 128i 6MT Sport
Join Date: Jan 2017
Location: Texas

iTrader: (0)

To clarify my earlier post that was quoted, my idle issue started the day I had headers installed, not the day I installed the tune. I thought the tune would fix it, but it didn’t make any difference with the idle. I replaced MAF, MAP, eccentric shaft sensor, coils, and the rear O2 sensors, cleaned and swapped VANOS solenoids, nothing worked. Unplugging an O2 sensor (front or rear) fixes it, as does resetting adaptations, so I know it’s sensor related.

I would expect that an N51 car with just a tune or MILVs + tune would not have idle issues since mine seem to be related to the headers.

Last edited by rowsdower; 09-19-2018 at 06:29 AM..
Appreciate 2
      09-18-2018, 08:55 PM   #25
rowsdower
Captain
rowsdower's Avatar
641
Rep
695
Posts

Drives: 2011 128i 6MT Sport
Join Date: Jan 2017
Location: Texas

iTrader: (0)

Quote:
Originally Posted by MattF407 View Post
If you mean, does the idle worsen the longer i drive the car? No, I drive varied commutes & weekend trips and have noticed no correlation between length of time and worsening of idle. I have also never observed correlations between spirited driving or running the AC and a worsening of idle either.

In my case, I do not believe that this is 100% tune related yet. If I do manage to resolve it, I will report back with my findings.
Another guy with headers had the same issue and mentioned that unplugging the rear O2 sensors fixed it. I can confirm this fixes my idle issue too, but I don’t know how else it affects the car so I have them plugged in.
Appreciate 3
      09-19-2018, 09:55 AM   #26
atmosphericM
Basic Bimmer
United_States
518
Rep
935
Posts

Drives: E92 328i 6MT ///M
Join Date: Sep 2017
Location: B'ham

iTrader: (1)

Garage List
Quote:
Originally Posted by MattF407 View Post
There are a few floating around with this, my N51 w/BPC stage 2 Tune has ~500 miles since Tune and reset of adaptations & I have an intermittent rough idle. My idle at good times fluctuates less than 150-300 rpm, with the bad around 400-700 rpm. The car never kills and still performs beautifully otherwise. With no definite evidence on what is causing the problem, I have two areas I am looking into for now to make sure it's not something stupid or simple. All in all, I regret nothing and would do it again even if told there would be an idle issue. I should also note I have days with perfect idles for my entire commute, which makes me wonder what is different drive to drive.


1) We have a SAP for emissions that N52 do not. I removed this system in the process of installing headers.

2) Damaged or bad O2 sensors, MAF sensor, or plugs/coils.

If these don't put me right, then back to the drawing board we go. It would be beneficial if there is an N51 out there that did a MILVs+3IM Tune and if that resulted in the similar idle issues as us that went down the headers route.

Hope this helps inform your decision a little more, also look into kgolfs build I believe it was an N51 on AA tune and I don't recall any mention of issues.
Hey, thanks for the info!

Question: I see that you removed your SAI (SAP?) system. That's super awesome to hear. That is exactly what I also wanted to do when getting the tune, but I've yet to reach out to BPC about the details. 1) What did you use to block off the port on the engine? I think I've found a few blocking plates on the web but wasn't 100% sure if they would work or not... and 2) Was BPC able to "code/tune out" the CEL that would normally result from the SAI system not being in place?

Thanks in advance!
__________________
Black Sapphire 328i ///M Sport Coupé
Save the Manuals!
Appreciate 0
      09-19-2018, 09:59 AM   #27
atmosphericM
Basic Bimmer
United_States
518
Rep
935
Posts

Drives: E92 328i 6MT ///M
Join Date: Sep 2017
Location: B'ham

iTrader: (1)

Garage List
Hmm, sad to hear that most if not all are having issues with headers on an N51. I'd really like that additional 15 whp from headers on top of the MILVS. But perhaps just deleting the secondaries and keeping the OE headers might be the way to go. =/

That's interesting about unplugging the rear O2 sensors... IIRC they're only there to check that the cats are working properly. If one is running catless headers, I would assume that the appropriate tune would essentially negate those sensors' function. Then again, I'm no tuner and I have no idea exactly what the sensors or tune really do in entirety.

hassmaschine is a genius when it comes to how these DME's work so I'm gonna try to bring him in here for a little insight. Maybe we can get Bob@BPC or Phil@BPC to chime in, too...
__________________
Black Sapphire 328i ///M Sport Coupé
Save the Manuals!

Last edited by atmosphericM; 09-19-2018 at 10:08 AM..
Appreciate 0
      09-19-2018, 12:56 PM   #28
Taskmaster
Banned
Japan
2463
Rep
9,004
Posts

Drives: M235i 6MT / E92 328 Msport 6MT
Join Date: Nov 2013
Location: Florida

iTrader: (6)

Quote:
Originally Posted by atmosphericM View Post
Hmm, sad to hear that most if not all are having issues with headers on an N51. I'd really like that additional 15 whp from headers on top of the MILVS. But perhaps just deleting the secondaries and keeping the OE headers might be the way to go. =/

That's interesting about unplugging the rear O2 sensors... IIRC they're only there to check that the cats are working properly. If one is running catless headers, I would assume that the appropriate tune would essentially negate those sensors' function. Then again, I'm no tuner and I have no idea exactly what the sensors or tune really do in entirety.

hassmaschine is a genius when it comes to how these DME's work so I'm gonna try to bring him in here for a little insight. Maybe we can get Bob@BPC or Phil@BPC to chime in, too...
You should call them, I've had good luck on the phone with them.
Appreciate 0
      09-19-2018, 07:32 PM   #29
rowsdower
Captain
rowsdower's Avatar
641
Rep
695
Posts

Drives: 2011 128i 6MT Sport
Join Date: Jan 2017
Location: Texas

iTrader: (0)

Quote:
Originally Posted by atmosphericM View Post
Hmm, sad to hear that most if not all are having issues with headers on an N51. I'd really like that additional 15 whp from headers on top of the MILVS. But perhaps just deleting the secondaries and keeping the OE headers might be the way to go. =/

That's interesting about unplugging the rear O2 sensors... IIRC they're only there to check that the cats are working properly. If one is running catless headers, I would assume that the appropriate tune would essentially negate those sensors' function. Then again, I'm no tuner and I have no idea exactly what the sensors or tune really do in entirety.

hassmaschine is a genius when it comes to how these DME's work so I'm gonna try to bring him in here for a little insight. Maybe we can get Bob@BPC or Phil@BPC to chime in, too...
My understanding is the postcat sensors do impact fuel trims a little bit. I also think that unplugging a sensor makes the car revert to an open loop mode, as does resetting adaptations. At least that is my theory. But I don’t know much about the software and am really talking out of my ass.

Getting BPC’s attention on the forum is hard since Phil and Bob have @ in their names so you can’t tag them. Maybe PM them or like Taskmaster said, call them.
Appreciate 1
      09-20-2018, 08:18 AM   #30
Phil@BPC
Lieutenant
Phil@BPC's Avatar
463
Rep
489
Posts

Drives: E39 M5/ E30 325is
Join Date: Nov 2017
Location: Raleigh, NC

iTrader: (0)

Garage List
2003 BMW M5  [0.00]
1990 BMW 325is  [0.00]
I would reach out to Bob directly on this one. He would be of more help than me sadly. He can be reached at webmaster@bimmerperformancecenter.com
Appreciate 1
      09-22-2018, 09:13 AM   #31
rowsdower
Captain
rowsdower's Avatar
641
Rep
695
Posts

Drives: 2011 128i 6MT Sport
Join Date: Jan 2017
Location: Texas

iTrader: (0)

Here's the other thread where someone mentioned the bouncing idle and removing the postcat O2 sensors as a solution. This guy has an AA tune though, not BPC, further reinforcing my belief that the idle issue is due to headers and not the tune. However it would be excellent if BPC had a tune that would fix the idle. Let us know what you find out from Bob@BPC.

https://www.1addicts.com/forums/show....php?t=1194190
Appreciate 1
      09-23-2018, 02:34 PM   #32
MattF407
Enlisted Member
United_States
39
Rep
44
Posts

Drives: 2013 Mineral Grey 128i
Join Date: Aug 2016
Location: Tampa, FL

iTrader: (0)

atmosphericM
Quote:
Originally Posted by atmosphericM View Post
1) What did you use to block off the port on the engine?
The N52 comes with a block off plate in place of the Secondary Air Pump (SAP or if you like Stupid A** Part).
Here is the complete list of parts I used:
11127521169 – Studs – 2
11727511542 – Block-off plate – 1
11727506214 – Gasket – 1
07119905949 – Locking Nuts – 2

There is one electrical connection that will need to be removed and zip tied off in a good spot, and from my research: Fuse for SAP is F89 (I have not disconnected, but do have notes it is connected to SAP Relay K6304 which is controlled by DME Control Unit A6000).
Quote:
Originally Posted by atmosphericM View Post
2) Was BPC able to "code/tune out" the CEL that would normally result from the SAI system not being in place?
Since I chose to handle it myself, I am not 100% sure. I did talk to a member of BPC staff about this before my header install. In our conversation, I believe it was mentioned this is not something the tune would resolve and would need to be coded out. Reach out to them and see, but I would wager they can sort you out on this.
Appreciate 1
      09-28-2018, 11:25 AM   #33
atmosphericM
Basic Bimmer
United_States
518
Rep
935
Posts

Drives: E92 328i 6MT ///M
Join Date: Sep 2017
Location: B'ham

iTrader: (1)

Garage List
Quote:
Originally Posted by MattF407 View Post
atmosphericM

The N52 comes with a block off plate in place of the Secondary Air Pump (SAP or if you like Stupid A** Part).
Here is the complete list of parts I used:
11127521169 – Studs – 2
11727511542 – Block-off plate – 1
11727506214 – Gasket – 1
07119905949 – Locking Nuts – 2

There is one electrical connection that will need to be removed and zip tied off in a good spot, and from my research: Fuse for SAP is F89 (I have not disconnected, but do have notes it is connected to SAP Relay K6304 which is controlled by DME Control Unit A6000).

Since I chose to handle it myself, I am not 100% sure. I did talk to a member of BPC staff about this before my header install. In our conversation, I believe it was mentioned this is not something the tune would resolve and would need to be coded out. Reach out to them and see, but I would wager they can sort you out on this.
Great info, thanks a ton! That's so weird to hear that the N52 head comes with a port for the SAP, considering that it didn't come with the pump affixed. (I wonder if the N52 in another country had the SAP/SAI?) Makes me wonder how different the N51 and N52 heads really are... I simply don't understand why they would cast in the port/route for an SAI system if they didn't plan on using an SAI system lol.

Regarding the electronics, do you have a CEL that resulted from deleting the SAP? I don't want any CEL's which is why I wonder about tuning/coding out. On an older car I wired in a resistor at the connection, but I'd like something cleaner for the bimmer.

I'll reach out to BPC for more info on the header surge as well as the SAP coding, but in full disclosure it might be a while before I do so because I don't plan on tackling these mods for another 6 months or so do to CPO warranty.
__________________
Black Sapphire 328i ///M Sport Coupé
Save the Manuals!
Appreciate 0
      09-28-2018, 12:16 PM   #34
atmosphericM
Basic Bimmer
United_States
518
Rep
935
Posts

Drives: E92 328i 6MT ///M
Join Date: Sep 2017
Location: B'ham

iTrader: (1)

Garage List
Just did a little research and wanted to chime in a bit with what I found / thought. Looks like a CEL will definitely happen (eventually) after removing the SAP/SAI. I'm seeing P1415/2D06 as the code, but I'm not 100% sure on that.

After thinking, I remember reading that the BMW actually looks at the O2 sensors to determine SAP performance, so installing a resistor on the SAP's plug wouldn't help with CEL's at all. I read of one guy using an O2 'simulator' to simulate what the O2 sensors should send to the DME for the first 30 seconds after starting (when the SAP would be running).. but that's not really the way I'd like to go, either.

Further, it looks as if many different potential problems with the engine can all result in the same fault code that the SAP failure (or removal) would throw, so perhaps simply removing that fault code from the DME tables (if that's even a thing) would not be a wise solution.

I'm starting to think that the only way to really do this well is to somehow change the tables in the DME's software to reflect N52 values.. but it's starting to get way over my head since I know so little about how the computer monitors and evaluates the SAI system's performance. Hmm.. I wonder if this is an area of the DME software that could simply be removed, resulting in an N51/N52 DME software hybrid of sorts.

.. just trying to understand all that I can before reaching out to the pros.
__________________
Black Sapphire 328i ///M Sport Coupé
Save the Manuals!

Last edited by atmosphericM; 09-28-2018 at 12:22 PM..
Appreciate 0
      09-28-2018, 03:03 PM   #35
rowsdower
Captain
rowsdower's Avatar
641
Rep
695
Posts

Drives: 2011 128i 6MT Sport
Join Date: Jan 2017
Location: Texas

iTrader: (0)

Quote:
Originally Posted by atmosphericM View Post
Great info, thanks a ton! That's so weird to hear that the N52 head comes with a port for the SAP, considering that it didn't come with the pump affixed. (I wonder if the N52 in another country had the SAP/SAI?) Makes me wonder how different the N51 and N52 heads really are... I simply don't understand why they would cast in the port/route for an SAI system if they didn't plan on using an SAI system lol.

Regarding the electronics, do you have a CEL that resulted from deleting the SAP? I don't want any CEL's which is why I wonder about tuning/coding out. On an older car I wired in a resistor at the connection, but I'd like something cleaner for the bimmer.

I'll reach out to BPC for more info on the header surge as well as the SAP coding, but in full disclosure it might be a while before I do so because I don't plan on tackling these mods for another 6 months or so do to CPO warranty.
Are the heads supposed to be different? I thought the N51/52 were mechanically the same other than compression ratio. CR can be changed with different pistons, which is almost certainly cheaper than building 2 different head designs.
Appreciate 0
      09-28-2018, 03:22 PM   #36
atmosphericM
Basic Bimmer
United_States
518
Rep
935
Posts

Drives: E92 328i 6MT ///M
Join Date: Sep 2017
Location: B'ham

iTrader: (1)

Garage List
^ Honestly I am not sure, but from what I've read on the interwebs, a different head is the cause for the slightly lower compression ratio, and supposedly the pistons are the same. Considering the SAP port being found on both heads though, I am starting to wonder, myself.

Some people also say that the N51's secondary cats are a higher cell count, thus being cleaner but also more restrictive - however I've never been able to find definitive info there, either. Of course other small changes exist, as well, such as slightly different radiator, the SAP/SAI system, variable length intake manifold, etc.
__________________
Black Sapphire 328i ///M Sport Coupé
Save the Manuals!
Appreciate 0
      09-28-2018, 03:35 PM   #37
atmosphericM
Basic Bimmer
United_States
518
Rep
935
Posts

Drives: E92 328i 6MT ///M
Join Date: Sep 2017
Location: B'ham

iTrader: (1)

Garage List
A quick trip to RealOEM.com gave me this, but I'm not sure what it's worth. Cyl. heads could be differently part numbered due to something as simple as whether or not that SAP block off plate is provided, I suppose. Perhaps N51 and N52 have different heads as well as pistons. At lest that's what the P/N's say...

11127591619 - N51 Cyl. Head
11257560131 - N51 Piston
11127591617 - N52 Cyl. Head
11257558528 - N52 Piston
__________________
Black Sapphire 328i ///M Sport Coupé
Save the Manuals!

Last edited by atmosphericM; 09-28-2018 at 03:41 PM..
Appreciate 0
      09-28-2018, 09:18 PM   #38
Taskmaster
Banned
Japan
2463
Rep
9,004
Posts

Drives: M235i 6MT / E92 328 Msport 6MT
Join Date: Nov 2013
Location: Florida

iTrader: (6)

You’re overthinking this. A choppy idle is absolutely livable.
Appreciate 0
      09-29-2018, 06:32 AM   #39
rowsdower
Captain
rowsdower's Avatar
641
Rep
695
Posts

Drives: 2011 128i 6MT Sport
Join Date: Jan 2017
Location: Texas

iTrader: (0)

Quote:
Originally Posted by Taskmaster View Post
You’re overthinking this. A choppy idle is absolutely livable.
This is completely subjective. Everyone uses their car differently and has different goals and expectations. What is livable to you may be unacceptable to someone else. For me, it's livable but not what I want to deal with. Although the car has more power and sounds better, I am ultimately less happy with it than stock.

Curious - do you have an N51 or an N52?
Appreciate 1
      09-29-2018, 10:00 AM   #40
Taskmaster
Banned
Japan
2463
Rep
9,004
Posts

Drives: M235i 6MT / E92 328 Msport 6MT
Join Date: Nov 2013
Location: Florida

iTrader: (6)

Quote:
Originally Posted by rowsdower View Post
This is completely subjective. Everyone uses their car differently and has different goals and expectations. What is livable to you may be unacceptable to someone else. For me, it's livable but not what I want to deal with. Although the car has more power and sounds better, I am ultimately less happy with it than stock.

Curious - do you have an N51 or an N52?
n52 - AND I had a choppy idle, it was fixed with another tune.
Appreciate 0
      09-29-2018, 11:26 AM   #41
rowsdower
Captain
rowsdower's Avatar
641
Rep
695
Posts

Drives: 2011 128i 6MT Sport
Join Date: Jan 2017
Location: Texas

iTrader: (0)

Quote:
Originally Posted by Taskmaster View Post
n52 - AND I had a choppy idle, it was fixed with another tune.
What tune gave you choppy idle, and what tune fixed it?
Appreciate 0
      09-30-2018, 02:54 AM   #42
Taskmaster
Banned
Japan
2463
Rep
9,004
Posts

Drives: M235i 6MT / E92 328 Msport 6MT
Join Date: Nov 2013
Location: Florida

iTrader: (6)

Quote:
Originally Posted by rowsdower View Post
What tune gave you choppy idle, and what tune fixed it?
BPC - but it happened when I installed my first Catless tune. It was an issue with a senor when went bad, but when away when I replaced the part and updated the tune.
Appreciate 0
      09-30-2018, 11:05 AM   #43
Tuxedo
Bowties r cool ▶:◀
Tuxedo's Avatar
United_States
1399
Rep
793
Posts

Drives: 09' 128i MT e88, 24'G05 X5 50e
Join Date: Apr 2014
Location: Chicago

iTrader: (0)

Garage List
I have had 2 N51 128's both have the idle issue, older coils amplify the issue but never removed it. in Dec 2012 BMW had a service bulletin SIB 12-09-12 for DME update to fix/minimize it. This started for N55 DCT and expanded to N51 in spring 13'. In Spring 14' new bulletin and DME update
Quote:
Originally Posted by Tuxedo View Post
The reason I came to this forum in the first place was this issue. It's been the result of 1 stall and numerous near stalls. this was on a 2011 with N51 auto. It is a mostly known issue on the 135i DCT and requires DME update and it's been a few years since ive looked at this update-
SI B12 09 12 Engine Electrical Systems April 2013 Technical Service
NOTE: SUPERCEDED BY SIB 12 15 14
N55 WITH DOUBLE-CLUTCH TRANSMISSION: IDLE FLUCTUATES WHEN STOPPED

After update 12 15 14 it was still there but never close to stall and mild in irritation levels. Bad Coils will amplify this idle issue too so if the current Coils have 30k replace them and then hit up BMW for an update.
If the idle issue is caused by a tune it's because the software BMW had in place to remedy has been replaced.
Attached Images
 
Appreciate 1
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 06:10 AM.




1addicts
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, 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