[Fritzer]

This has been happening on and off for the last couple months for me. The car has not thrown any codes or CEL for this. I am completely unsure of what could cause this. Any input would be appreciated.

2011 E90 LCI with N51 SULEV engine. Car was warm when the video was filmed, no accessories on except headlights, complete standstill with foot on the brakes and parking brake fully applied. Probably 2,500 miles since last oil change with Pentosin 5W-30.Listen closely before I change the gears and you can hear the rough idle, it sounds like it's pulsing.

The only thing I can think is bad MAF, O2 sensors, or crankshaft position sensor or something. But zero codes have been thrown for this. Could it possibly have to do with the transmission? Totally lost, any help or advice would be appreciated. Video embedded below.

[Fritzer]

[Fritzer]

[CTinline-six]

My car actually did this recently. I also have an N51. I have new plugs and coils and the car doesn't misfire. I've read it could be the VANOS solenoids. Mine has done it twice, both times it was after a cold start and while stopped at a light.

[AoS810]

Update from me, took my vehicle to the dealership and they replaced the exhaust Vanos solenoid, Valve cover, and valve cover gasket under the SULEV warranty as my car was throwing 2A87 and the CCV had gone bad causing a loud whistling sound.

Unfortunately my car still has this slight rumble that I can feel at idle. I'll keep an eye out to see if it still does the weird RPM dips on gear selection.

I wonder if I need to switch out my spark plugs and coils? It's been 70K miles on my sparks and original coils at 142K miles. I'm not getting any codes at all which is nice, but something still feels a bit off.

*EDIT* I also did a fresh oil change with Castrol 0w-40 after the dealership did their warranty work.

[m_thompson]

Originally Posted by AoS810

I wonder if I need to switch out my spark plugs and coils? It's been 70K miles on my sparks and original coils at 142K miles.

Plugs and coils should also be covered under your SULEV warranty, but without codes it is unlikely the dealership will do anything more for you.

[AoS810]

Originally Posted by m_thompson

Plugs and coils should also be covered under your SULEV warranty, but without codes it is unlikely the dealership will do anything more for you.

Yep, I had mental gymnastics this morning if I should just buy and replace myself.. best case scenario I replace them and the bad idle goes away and I know there's nothing weird going on with the car. Or I wait till 150K miles to replace.. and it doesn't fix it, in which case maybe I could have had it fixed under SULEV? Not throwing codes though so not sure what can be done by dealership like you said. What to do.. what to do

[Fritzer]

Originally Posted by m_thompson

Plugs and coils should also be covered under your SULEV warranty, but without codes it is unlikely the dealership will do anything more for you.

This is correct.

[m_thompson]

Originally Posted by m_thompson

Plugs and coils should also be covered under your SULEV warranty, but without codes it is unlikely the dealership will do anything more for you.

I looked again at some of the lists of covered items. I see coils, but I don't see plugs.

[lowrydr310]

I get this exact behavior occasionally on my N52. I want to say about twice a month seemingly at random, I can't correlate it to any specific condition. New plugs and coils didn't make any difference.

I doubt it's MAF or O2 sensors causing it. It could be the crankshaft position sensor or eccentric shaft sensor, though I remember reading somewhere aroudn here about a person who had a similar issue and replacing the ESS still didn't fix it.

I also read it could be the VANOS solenoids. AoS810 stated that he had his exhaust solenoid replaced and the problem still persisted, but I wonder if the intake solenoid is contributing to the issue? I cleaned both of my VANOS solenoids recently and while they weren't really dirty there was a coating on them that I cleaned off. I didn't notice any difference whatsoever after reinstalling them.

What about the VANOS check valves? Could they be contributing to the issue?

Another symptom I have in addition to this occasional stumble is an occasional slight pinging/rattling when accelearting from slow speeds. It sounds like detonation but it's pretty mild compared to the knocking engines I've owned in the past. I believe I have a faulty CCV/oil separator and I wonder if this pinging is a slight lean condition from oil vapors getting into the combustion chamber?

[AoS810]

Originally Posted by lowrydr310

I doubt it's MAF or O2 sensors causing it. It could be the crankshaft position sensor or eccentric shaft sensor, though I remember reading somewhere aroudn here about a person who had a similar issue and replacing the ESS still didn't fix it.

What about the VANOS check valves? Could they be contributing to the issue?

Just to add more experience, I've cleaned my MAF with CRC with no change. I replaced my crankshaft position sensor 1.5 years ago so I'm hoping that wouldn't go bad already.. When I got my valve cover replaced due to CCV issue, the dealership didn't mention anything about my ESS going bad and they replaced the gaskets for the ESS and valvetronic motor.

I'm going to wait until my next oil change to replace the Vanos filters / check valves and see if that helps.

[AoS810]

Update, so I've been driving the car daily and to my pleasant surprise it seems like the issues I previously described in this thread have disappeared. The slight rumble at idle after the dealership replaced my valve cover and exhaust vanos solenoid is now completely gone. I'm also not noticing any weird gear shift issues (the RPM dip in Fritzer's video) anymore.

I'm not sure what changed between me picking up the car on 4/20/19, adaptations? I have zero codes. But its back to being completely smooth with no odd behavior at least for the past week. I'll post another update if I notice anything weird again.

[AoS810]

Update, this issue is back for me. Not sure why it was okay for 2-3 weeks but I'm back to slightly rough idle and the pulsing/RPM surge on especially when going into reverse after the car is warmed up.

Anyone try anything else that fixed this? A new thread was recently started with what seems like similar issues. https://www.e90post.com/forums/showthread.php?t=1631757

[CTinline-six]

I had this problem on my N51 (as noted above). Even after new plugs and coils it was still there, mainly when coming to a stop light with a cold engine.

I had my car at the dealership for the valve cover/gasket replacement covered by SULEV warranty a month or so ago, and noted to the service adviser the rough idle/surge in gear and what I had replaced. They did a software update according to the paperwork, and the issue has not returned yet. I've put about 5,000 miles on the car since, including a 2600 mile road trip with no surge.

[AoS810]

Originally Posted by CTinline-six

I had this problem on my N51 (as noted above). Even after new plugs and coils it was still there, mainly when coming to a stop light with a cold engine.

I had my car at the dealership for the valve cover/gasket replacement covered by SULEV warranty a month or so ago, and noted to the service adviser the rough idle/surge in gear and what I had replaced. They did a software update according to the paperwork, and the issue has not returned yet. I've put about 5,000 miles on the car since, including a 2600 mile road trip with no surge.

Thanks for the quick response! Was the software update covered under the SULEV warranty? I wonder if they'll charge me because I didn't get that update at the same time as the valve cover/gasket replacement that they did under SULEV.

Also, does your paperwork note what exactly was updated so I can give them as reference?

[CTinline-six]

Originally Posted by AoS810

Thanks for the quick response! Was the software update covered under the SULEV warranty? I wonder if they'll charge me because I didn't get that update at the same time as the valve cover/gasket replacement that they did under SULEV.

Also, does your paperwork note what exactly was updated so I can give them as reference?

Attached is a picture of what was noted on my service receipt. They charged me an hour of labor to do the update. It gives the DME software version. Not sure if that helps or if this will solve the problem but it definitely made a difference with my car.

[maf330xi]

I have this exact issue right now. I stop at a red light, brakes fully pressed in and the RPM just shoots up just like your video.

Do you also have these symptoms:
- When you're coasting, does your RPM fluctuate?
- entire car shudders when changing gears (automatic). Usually lower gears.

[AoS810]

Originally Posted by maf330xi

Do you also have these symptoms:
- When you're coasting, does your RPM fluctuate?
- entire car shudders when changing gears (automatic). Usually lower gears.

- When coasting my RPM does NOT fluctuate. That almost sounds like a crankshaft position sensor going bad? Definitely scan for codes and see if that pops up.
- My car does not shudder when changing gears (GM trans). The only "shuddering" is upon going from P to R, or from D to R, sometimes P to D and the slightly rougher idle. I haven't experienced anything odd shifting between gears, even lower ones.

[AoS810]

Update on what I've done to try and fix this.

I've performed the below steps with no success. Just wanted to outline this shotgun approach as the below won't necessarily fix this issue:

1) Replaced spark plugs with NGK 1208
2) Replaced ignition coils with Delphi DEL-GN10571 (I was on original Bosch)
3) Replaced both Vanos filters 11367541692 (my old ones looked very clean for 148K miles)
4) Replaced my oil fill cap w/ the BMW genuine redesign 11128655331 (because I like to waste money)
5) Cleaned the Vanos intake solenoid w/ brake cleaner and new gaskets. My exhaust solenoid was already replaced under SULEV warranty.

I wanted to do the above before I went to the dealership because it was about time anyway. I have an appointment with my local dealership tomorrow and I will be following CTinline-six's recommendation to have the DME updated based off of BMW SIB 12-21-12. https://www.e90post.com/forums/showthread.php?t=847335

Wish me luck, if it's not fixed after the update then I'm at a complete loss for what is causing my issues. I still have no codes to go off of for this but the rough idle and RPM surge on gear selection change is consistently reproducible.

[AoS810]

Quick update, my car's still at the dealership. They've been able to reproduce the issue but again the car's not throwing any codes. My SA states the shop foreman is now working on it and going to take it on drives / extended drives with it hooked up to a scanner for data logging. They're also working with BMW NA to figure out what's happening.

I mentioned BMW SIB 12-21-12 again on the phone call but I don't want to be too pushy as I've been to this dealership for SULEV repairs / basic maintenance and they're good people. Stated they want to find out exactly what is happening so that they're not just guessing at repairs and billing me for it which I appreciate.

I'm scared guys

[Fritzer]

Originally Posted by AoS810

Quick update, my car's still at the dealership. They've been able to reproduce the issue but again the car's not throwing any codes. My SA states the shop foreman is now working on it and going to take it on drives / extended drives with it hooked up to a scanner for data logging. They're also working with BMW NA to figure out what's happening.

I mentioned BMW SIB 12-21-12 again on the phone call but I don't want to be too pushy as I've been to this dealership for SULEV repairs / basic maintenance and they're good people. Stated they want to find out exactly what is happening so that they're not just guessing at repairs and billing me for it which I appreciate.

I'm scared guys

Man, I appreciate all the work you are doing while reporting it. Are they charging you or do you think it's all under SULEV warranty? Which dealer up in OC are you going to? I might take mine there if they find a solution, as I'm still under SULEV warranty as well.

[AoS810]

I just got my car back yesterday and it seems to be a lot better. I still have a slight rough idle after startup but I haven't been able to reproduce the gear shift fluctuation yet.

The dealership updated the engine DME software. I scanned the car and I'm getting a brand new fault code in the transmission module, CF17 that wasn't present prior to the update. I've attached pictures of what I found online for this code.

This has to be related to the DME update. Anyone have any experience with this? When I erase the code, it just comes back on the next start up. In one of the pictures I attached, it states missing calibration? Makes me feel like the dealership job was incomplete.

*EDIT* the messages in the terrible pictures state:

CF17 No message from JBBF. Vehicle mode, receiver DKG/EGS, transmitter DSC/DME-DDE
CF17 GM6, EGS; CF17 fault after programming (calibration between ISTA/D and ISTA/P missing)