RPM fluctuating constantly after header install + tune

claasmi · 07-26-2017, 08:25 PM

I just installed AA headers + AA offroad tune. On cold start the engine idles fine, but after its warmed up it fluctuates up and down constantly about once a second. At idle the needle dips maybe 100 - 200 rpm down and back up, over and over again very consistently. In gear at low RPM I can also feel it fluctuating. The only code I am getting is:

Fuel Pump:
CED4
Externer Fehler: CAN-ID 0xAA (TORQUE_3) fehlte(e)

The headers were installed by a reputable shop and I cleared all adaptations after putting the tune on. I did just yesterday also install a 3 stage intake (myself) but it was running totally fine before the headers went on.

Any ideas what the issue could be?

desertman123 · 07-26-2017, 11:46 PM

Double check EVERYTHING and make sure there's no vacuum leaks, particularly on the intake side. Check vacuum lines, clean MAF, clean VANOS solenoids. Make sure your oil breather isn't cracked.

Also pull the battery terminal for like 15 minutes. Maybe you just need to clear adaptations since you have a pretty major change to the breathing of the engine?

claasmi · 07-27-2017, 10:40 AM

I had an issue after installing the 3 stage intake a few days before (turns out I just forgot to plug a hose in) so I had already thoroughly checked all the connections on the intake side. Also I did clear all adaptations already using BAV cable. Is there any chance this would be caused by something on the exhaust side? (a leak either between the headers and the engine or the headers and the mid pipe) as this was the only part I didn't personally do and check myself. It seems too much of a coincidence for it to be something not directly related to the headers as everything was totally fine right up until the headers and tune went on.

crowtrobot · 07-27-2017, 10:48 AM

Try pulling the battery cable and let it sit for a while. I had some pretty bad idle surging after I did the AA headers, tried doing the pedal dance as suggested by AA to reset the adaptations, but this didn't help.

Idle surge went away after disconnecting the battery for a different job.

If not that, perhaps the shop mixed up the O2 sensor connections? If you can check the O2 sensor output, my recollection is that one will be max'd out if they are reversed.

claasmi · 07-27-2017, 11:27 AM

Well, I just went for a drive on the highway for a bit, maintaining steady rpm around 3000 for about 20 minutes and the issue seems to be gone now. Now I'll just wait and see if it comes back.

Bimmer-Bob · 07-30-2017, 09:57 AM

Check for codes, too. I had surging idle when warm - it started after a header install, so I figured it was related, and it sort of seemed to come and go. I think to some extent, it's normal as the car learns to adjust fueling, but I finally checked codes and had several faults stored related to the eccentric shaft sensor (no CEL or SES). I changed that and it seems to have improved significantly (although it took several drive cycles).

Just a thought - I think it never hurts to check codes on these cars as a regular part tof your diagnostics, no matter what the issue is. After all, that's where the dealer techs are going to start!

desertman123 · 07-30-2017, 11:13 AM

Quote:

Originally Posted by Bimmer-Bob

Just a thought - I think it never hurts to check codes on these cars as a regular part tof your diagnostics, no matter what the issue is. After all, that's where the dealer techs are going to start!

Ain't that the truth!!! I scanned my parent's 5 series the other day, just to see what popped up.

Multiple misfire codes!! Even though it never shook, felt fine, no CEL/SES, etc. When I mentioned it to my mom she figured that's why she feels like she's always filling up the gas tank.

needexhaust · 07-30-2017, 03:43 PM

Which device do you guys use to scan codes?

Bimmer-Bob · 07-30-2017, 04:56 PM

Quote:

Originally Posted by needexhaust

Which device do you guys use to scan codes?

I use the same laptop with Simon 3 cable and software that I used to load the AA tune. I also have INPA and NCS Expert loaded on the same laptop (have to use a different cable, though), but I find the Simon 3 to be the fastest and easiest way to check and clear codes. A handheld device would probably be even easier and quicker, but I already had what I'm using.

claasmi · 07-30-2017, 06:38 PM

Quote:

Originally Posted by needexhaust

Which device do you guys use to scan codes?

I use the Bavarian Technic cable and software. Its really overkill for what I use it for, but it can do a lot things like read sensor values in real time and send control signals like resetting adaptations. The Simon3 tool never really worked for me to do anything other than uploading the tune. I was getting codes using the Bav cable when the Simon3 tool didn't show anything. The only issue I found with the Bav cable was it never worked on Windows 7 for me, I ended up having to use a VM with Windows XP. This might be because I am running Windows in bootcamp on a Macbook, although the Simon3 cable works fine without a VM.

desertman123 · 08-01-2017, 09:15 AM

Quote:

Originally Posted by needexhaust

Which device do you guys use to scan codes?

CarlyBMW, because I'm a cheapass and also don't feel like learning how to use all the fancy BMW tools.

needexhaust · 08-07-2017, 02:46 PM

Quote:

Originally Posted by desertman123

CarlyBMW, because I'm a cheapass and also don't feel like learning how to use all the fancy BMW tools.

This is what I was looking for 😂

07-26-2017, 08:25 PM	#1
claasmi Private 37 Rep 56 Posts Drives: 2011 128i 6MT Join Date: Jun 2015 Location: Toronto iTrader: (0) Garage List 2011 128i [0.00]	RPM fluctuating constantly after header install + tune I just installed AA headers + AA offroad tune. On cold start the engine idles fine, but after its warmed up it fluctuates up and down constantly about once a second. At idle the needle dips maybe 100 - 200 rpm down and back up, over and over again very consistently. In gear at low RPM I can also feel it fluctuating. The only code I am getting is: Fuel Pump: CED4 Externer Fehler: CAN-ID 0xAA (TORQUE_3) fehlte(e) The headers were installed by a reputable shop and I cleared all adaptations after putting the tune on. I did just yesterday also install a 3 stage intake (myself) but it was running totally fine before the headers went on. Any ideas what the issue could be?
	Appreciate 0 Tweet Quote

07-26-2017, 11:46 PM	#2
desertman123 E82 Mudflap Ambassador 2214 Rep 2,219 Posts Drives: '08 128i Join Date: May 2016 Location: Orlando, FL iTrader: (0) Garage List 1992 Honda Beat [9.50] 2008 BMW 128i [10.00] 2014 BMW 528i [10.00]	Double check EVERYTHING and make sure there's no vacuum leaks, particularly on the intake side. Check vacuum lines, clean MAF, clean VANOS solenoids. Make sure your oil breather isn't cracked. Also pull the battery terminal for like 15 minutes. Maybe you just need to clear adaptations since you have a pretty major change to the breathing of the engine? __________________ My 2008 128i - Sparkling Graphite/Beige - Sport pkg - 6MT - Click me! Parents' 2014 528i - Mineral White/Ivory White - fully loaded Instagram @Andreys_128i and @Honda.Bito
	Appreciate 0 Quote

07-27-2017, 10:40 AM	#3
claasmi Private 37 Rep 56 Posts Drives: 2011 128i 6MT Join Date: Jun 2015 Location: Toronto iTrader: (0) Garage List 2011 128i [0.00]	I had an issue after installing the 3 stage intake a few days before (turns out I just forgot to plug a hose in) so I had already thoroughly checked all the connections on the intake side. Also I did clear all adaptations already using BAV cable. Is there any chance this would be caused by something on the exhaust side? (a leak either between the headers and the engine or the headers and the mid pipe) as this was the only part I didn't personally do and check myself. It seems too much of a coincidence for it to be something not directly related to the headers as everything was totally fine right up until the headers and tune went on.
	Appreciate 0 Quote

07-27-2017, 10:48 AM	#4
crowtrobot First Lieutenant 366 Rep 317 Posts Drives: 2008 M3 Join Date: Sep 2015 Location: Philly iTrader: (1)	Try pulling the battery cable and let it sit for a while. I had some pretty bad idle surging after I did the AA headers, tried doing the pedal dance as suggested by AA to reset the adaptations, but this didn't help. Idle surge went away after disconnecting the battery for a different job. If not that, perhaps the shop mixed up the O2 sensor connections? If you can check the O2 sensor output, my recollection is that one will be max'd out if they are reversed.
	Appreciate 0 Quote

07-27-2017, 11:27 AM	#5
claasmi Private 37 Rep 56 Posts Drives: 2011 128i 6MT Join Date: Jun 2015 Location: Toronto iTrader: (0) Garage List 2011 128i [0.00]	Well, I just went for a drive on the highway for a bit, maintaining steady rpm around 3000 for about 20 minutes and the issue seems to be gone now. Now I'll just wait and see if it comes back.
	Appreciate 0 Quote

07-30-2017, 09:57 AM	#6
Bimmer-Bob ! 693 Rep 3,266 Posts Drives: 2010 128i Join Date: Feb 2010 Location: Anacortes, WA iTrader: (4) Garage List 2010 BMW 128i (E82) [9.25]	Check for codes, too. I had surging idle when warm - it started after a header install, so I figured it was related, and it sort of seemed to come and go. I think to some extent, it's normal as the car learns to adjust fueling, but I finally checked codes and had several faults stored related to the eccentric shaft sensor (no CEL or SES). I changed that and it seems to have improved significantly (although it took several drive cycles). Just a thought - I think it never hurts to check codes on these cars as a regular part tof your diagnostics, no matter what the issue is. After all, that's where the dealer techs are going to start! __________________ ____________________________ My Build Thread
	Appreciate 0 Quote

07-30-2017, 03:43 PM	#8
needexhaust Enlisted Member 6 Rep 45 Posts Drives: 2012 BMW 128I Join Date: Sep 2016 Location: Mississauga iTrader: (0)	Which device do you guys use to scan codes?
	Appreciate 0 Quote