[BMW20plusYears]

09 335xi Sport with Stage 1 Aggressive Cobb, AFE intake, catch can, aluminum charge pipe, 93 octane, 89k miles

Rough idol, drives smooth lower speeds, above 60mph hard accelerate equals studdering at high RPMs only, no fault codes. Previous fault codes showed lambda post cat O2 sensors and boost leak, fixed both. Been happening for 10k+ miles. Two dealerships and local garage have no idea. Still not fixed.

In the last 10k miles, did following in steps to try and fix, all certified BMW at dealerships except charge pipe and catch can I did:
HPFP
Spark Plugs
Injectors (newer revised)
Coil Pack
Walnut blasting
Catch Can
Oil changes
Both post cat O2 sensors
Aluminum Charge Pipe
VANOS solenoids

Re-flashing the COBB with the same map seems to help sometimes. Maybe running lean, but why? Seems to be an issue with standard and flashed ECUs.

* Wondering ratio of those having similar problems that have mods vs. no mods

[535XrayIndigo]

I am having similar issues. Has anyone here tried changing to ngk plugs and adjusting them incrementally till the issue goes away. It appears there is a common cause from all of the ones I see here. Bosch plugs. Please let me know if anyone here has tried this? I looked at some reviews of the NGKs on amazon and FCPeuro and many state they helped or eliminated this pesky idle issue.

[Gugz]

My e93 320i has 90k miles, it started jerking on the high gears slight loss of power but pulls normal if you change down, then now engine check light goes on when engine warms up and the whole car is vibrating more than normal. can see the gear stick shaking.
Bought this a month ago, any help i am new hear. I have no warranty etc

[torrque]

Originally Posted by BMW20plusYears

09 335xi Sport with Stage 1 Aggressive Cobb, AFE intake, catch can, aluminum charge pipe, 93 octane, 89k miles

Rough idol, drives spooth lower speeds, above 60mph hard accelerate equals studdering, no fault codes. Previous fault codes showed lambda post cat O2 sensors and boost leak. Been happening for 10k+ miles. Two dealerships and local garage have no idea. Still not fixed.

In the last 10k miles, did following in steps to try and fix, all certified BMW at dealerships except charge pipe and catch can:
HPFP
Spark Plugs
Injectors (newer revised)
Coil Pack
Walnut blasting
Catch Can
Oil changes
Both post cat O2 sensors
Aluminum Charge Pipe
VANOS solenoids

Re-flashing the COBB with the same map seems to help sometimes. Maybe running lean, but why? Seems to be an issue with standard and flashed ECUs.

If you reflash and it works *sometimes* you have your answer. Put the stock map back on, and take it from there.

[BMW20plusYears]

Originally Posted by torrque

If you reflash and it works *sometimes* you have your answer. Put the stock map back on, and take it from there.

Thanks torrque. I Wonder how many others that are having problems are using COBB, JBL, etc.? Perhaps resetting the ECU, the learning?

My problem went away completely, two things changed in the last 2 weeks. I noticed this happened as I went into Summer. Lately, much colder air temps, been in the 50's down from the high 80's, so much more air mass. I also stopped adding octane booster. Did either or both solve it? I'll report back if the problems comes back, but for now it's gone.

[07e92nick]

Hey everyone! super new to the forum and N54 game so I apologize if I make any newbie mistakes . I got my 07' 335i in early December and about a week or two ago its developed a rough idle. Sometimes it bounces around 950-750 and other times it goes from 900 to under 500 with a pretty good shake right behind it, to me showing a clear sign of a misfire.

Ive used Protool to scan the car and its throwing absolutely zero codes Ive spent a lot of time looking into whats caused the idle (Ignition coils, spark plugs, Throttle body ICV, intake valve walnut blast, Dirty/ Failing Vanoss, MAP sensor, Vacuum leaks, HPFP and lastly the dreaded $1200 Index 12 injectors

Ive pretty much read this entire forum but I still wanted to ask everyone what I should do since my diagnostic tool is throwing no codes. Ive ran some high quality fuel injector cleaner but no luck what do you guys think is the issue?

[coochjr]

Originally Posted by 07e92nick

Hey everyone! super new to the forum and N54 game so I apologize if I make any newbie mistakes . I got my 07' 335i in early December and about a week or two ago its developed a rough idle. Sometimes it bounces around 950-750 and other times it goes from 900 to under 500 with a pretty good shake right behind it, to me showing a clear sign of a misfire.

Ive used Protool to scan the car and its throwing absolutely zero codes Ive spent a lot of time looking into whats caused the idle (Ignition coils, spark plugs, Throttle body ICV, intake valve walnut blast, Dirty/ Failing Vanoss, MAP sensor, Vacuum leaks, HPFP and lastly the dreaded $1200 Index 12 injectors

Ive pretty much read this entire forum but I still wanted to ask everyone what I should do since my diagnostic tool is throwing no codes. Ive ran some high quality fuel injector cleaner but no luck what do you guys think is the issue?

So since your not throwing codes, in the morning before you drive it pull the plugs on the car and check to see if they have fuel on them and if it does that injector needs to be replaced. Do that first that way you already know it's the injector instead of buying plugs and coils and then having to buy injectors. But if it's not throwing codes now and it is a injector it will soon and it will show a misfire code more than likely.

[BMW20plusYears]

If you are using COBB or other chips to that add boost pressure, and your car is hesitating at high RPMs, and you didn't upgrade your FMIC, then that's the likely problem. When it gets heat soaked, electronics will step in to limit power. I posted in this thread earlier, as the problem I was having was in the Summer, and went away when it got colder. I recently installed a 7" FMIC (running COBB Stage 1 Aggressive, boosts to 17 psi) and it's been getting warm here, no issues so far in 70 degree driving, will see when it gets to 90.

[BMW20plusYears]

"Hey everyone! super new to the forum and N54 game so I apologize if I make any newbie mistakes"...

My rough idle went away when I replaced the solenoids: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[danfratamico]

Originally Posted by BMW20plusYears

"Hey everyone! super new to the forum and N54 game so I apologize if I make any newbie mistakes"...

My rough idle went away when I replaced the solenoids: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Did you try cleaning them first with MAF cleaner?

[BMW20plusYears]

Originally Posted by danfratamico

Did you try cleaning them first with MAF cleaner?

I probably could have, they had just over 80k miles, I hear that usually works but sometimes temporary, so I just opted to replace them while I was doing other work.

[danfratamico]

Originally Posted by BMW20plusYears

I probably could have, they had just over 80k miles, I hear that usually works but sometimes temporary, so I just opted to replace them while I was doing other work.

Were you getting any VANOS codes? I have a rough idle and I'm wondering if I should change them if not getting any codes.

[BMW20plusYears]

Originally Posted by danfratamico

Were you getting any VANOS codes? I have a rough idle and I'm wondering if I should change them if not getting any codes.

I'm sorry but I can't remember. I was looking through this thread and several had suggested it, especially for cars approaching 80k miles. I was dealing with a rough idle and my car was studdering at high RPM. The rough idle stopped after the new solenoids, but the high RPM studdering persisted through last Summer but stopped as Winter approached. I found out that because I am boosting to 17 psi with the Cobb, the stock intercooler was getting heat-soaked and power was purposefully limited to compensate. I recently installed and ARM Motorsports 7" FMIC with upgraded 3" hoses and had a couple of 80+ degree days and the high RPM studdering is not only gone, but my car is even more of a beast! I can't stress enough that anyone using JB, Cobb, etc. to boost the turbos, you will need an upgraded charge pipe, FMIC and hoses, otherwise, way too much heat and/or a blown charge pipe.

On another note, I strongly suggest using Cataclean for high mileage cars, follow the instructions (lots of people don't per the YouTube videos I've seen). https://www.sciencedirect.com/scienc...15098615302469

[Sconley]

Originally Posted by AWD Addict

For the record, I went stumble free after a service soon after my last post in this thread.

Then about 60 days ago, I had some work done (new flash, new plugs, oil change, etc.) and they brought the car down the ramp for me, and it was misfiring something fierce.

They sent me home in a loaner, and hte next day they said they hadn't reset something after then new plugs were installed ( ). Well, sure enough, the car has the stumbling idle again.

That, combined with people talking about ignition (plugs and coilpacks), I'm wondering if this isn't a fuelling or valving issue at all, but an ignition one? Is this a bad connection/misfire type of issue?

Anyone else had any success getting rid of the stumble?

My stumble had to do with my transmission. Whenever I pushed in the clutch it would cut out.

[kingcloudix]

Someone please help...

Car Stats: 2010 335xi Coupe (MHD Stage 2+ Version 9, K&N Drop in Filter, Catless Downpipes, VRSF Intercooler, VRSF Charge Pipe, HKS Blow off Valve)

Car was initially throwing a lean code on bank 2 and after some time on bank 1. Whenever I clear the code it always comes back on bank 2 and after more time bank 1. No air leaks.

So, I changed the plugs, coils, and all O2 sensors.

A day later... the car idles rough on initial start (for about 10 seconds) but drives fine until it hits operating temp. Once it hits normal operating temperature it misfires at idle/at a stop...guaranteed. If it idles too long and I try to pull off...the engine shakes. But once the car is moving I don't feel a misfire. At this point I'm driving on the highway only (praying no traffic) and constantly trying to catch green lights so I that I wont have to stop in order to keep from causing any further damages. (Garaging not an option right now). It also seems like the temperature moves a lot faster (toward normal operating) at idle.

None of these issues were occurring prior to new coils, plugs, and sensors. Only issue I had was SES light for bank 2 lean and bank 1 lean (eventually). The car ran fine. I only started to replace things because emission test failed.

Please help if anyone can.

[Mizkizaa]

Originally Posted by kingcloudix

Someone please help...

Car Stats: 2010 335xi Coupe (MHD Stage 2+ Version 9, K&N Drop in Filter, Catless Downpipes, VRSF Intercooler, VRSF Charge Pipe, HKS Blow off Valve)

Car was initially throwing a lean code on bank 2 and after some time on bank 1. Whenever I clear the code it always comes back on bank 2 and after more time bank 1. No air leaks.

So, I changed the plugs, coils, and all O2 sensors.

A day later... the car idles rough on initial start (for about 10 seconds) but drives fine until it hits operating temp. Once it hits normal operating temperature it misfires at idle/at a stop...guaranteed. If it idles too long and I try to pull off...the engine shakes. But once the car is moving I don't feel a misfire. At this point I'm driving on the highway only (praying no traffic) and constantly trying to catch green lights so I that I wont have to stop in order to keep from causing any further damages. (Garaging not an option right now). It also seems like the temperature moves a lot faster (toward normal operating) at idle.

None of these issues were occurring prior to new coils, plugs, and sensors. Only issue I had was SES light for bank 2 lean and bank 1 lean (eventually). The car ran fine. I only started to replace things because emission test failed.

Please help if anyone can.

I would make sure you didnt swap the 02 banks on accident. Other than that I would say it's injectors if you've replaced everything else. Maybe try taking off the tune if you can to weed that out. Could be the Fuel pump control module or pumps, but if you're not getting those codes I would think its unlikely.

[AWD Addict]

Just a little #Throwback Thursday. For the record, it's insane I'm posting in this thread 10 year after it was started.

Back to the #TBT, from a few pages ago, this is for anyone that's just getting into this issue. Long story short, smoke test the intake system FIRST. I'm pretty sure my inlet leak, valve cover gasket leak, cracked manifold and cracked charge pipe were 90% of my issue. The oil that gets into our intake system destroys that plastic. It's not an if it will happen, it's a when it will happen.

Then consider plugs and a walnut blast, if you haven't had one in 40k miles. After that, you need to start looking at the more expensive stuff, like coilpacks and injectors.

https://www.e90post.com/forums/showp...&postcount=336

[Azntincan]

Got the SES, Just changed the bank 1 upstream. Will be changing the spark plugs soon(waiting for shipment)

Would you guys suggest to change any other oxygen sensors?

Code: 2C31, 2C27, 29F4, 29F5 and 29E0

[renoir408]

After 3 months of headaches and a lot of expenses (BMW Spark Plugs, Injectors test bench, Injectors index 12, BMW Coil Pack, Walnut blasting, Oil changes, VANOS solenoids clean, Boost Solenoids, Vacuum lines), with no effect, I finally solved this problem of rough idle and exhaust pops.

I set up the BMW Bosh spark plugs gap to 0,9mm and like a miracle everything works well. Any misfires at high turns and stable idle at 650rpm w/o air conditioner and 700rpm with. Maybe this is a very high gap for the plugs, but it works like a charm.

I hope it can help others with the same issue.

[Saif2018]

Originally Posted by renoir408

After 3 months of headaches and a lot of expenses (BMW Spark Plugs, Injectors test bench, Injectors index 12, BMW Coil Pack, Walnut blasting, Oil changes, VANOS solenoids clean, Boost Solenoids, Vacuum lines), with no effect, I finally solved this problem of rough idle and exhaust pops.

I set up the BMW Bosh spark plugs gap to 0,9mm and like a miracle everything works well. Any misfires at high turns and stable idle at 650rpm w/o air conditioner and 700rpm with. Maybe this is a very high gap for the plugs, but it works like a charm.

I hope it can help others with the same issue.

You gapped the OEM 3 prong Bosch plugs?

[renoir408]

Originally Posted by Saif2018

You gapped the OEM 3 prong Bosch plugs?

Yes.

[Saif2018]

Originally Posted by renoir408

Yes.

They are pre gapped, they're not supposed to be gapped.

Your masking the problem and those plugs probably won't last long.