[335i E92]

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?

Ok here's the situation... I have the rough idle exact same stumbling and rpm jumps up from 600rpm to 750rpm when the car is warm. I have spent the last 18 months trying to fix this issue that started imeediatley after changing the original plugs.

Firstly what we are all experience is NOT hardware related its 100% software. I've had 2 further sets of plugs, 6 injectors & 6 coils, full engine out and head off decarb over the last 18months an nothing has fixed the issue. This is 100% an adaptation issue.

Last week my local Indy brought a BMW main dealer master tech down to try to help the diagnosis. After listening to the symptoms and the fact that none of the above have fixed it along with the major clue that it happened straight after the plug change he has come up with what sounds like the fix.

I am booked in with him next week and was gonna start new thread to tell the masses but I'm that convinced it's going to fix he issue I'll spill the beans now and hopefully it'll be the end of this f@&king annoying rough Idle for good for us all!!

I've read every n54 rough idle post there is and have tried every adaptation available, even Mr5's BT cable reset which helped some didn't do shit for me.

However there is a reset that the master tech thinks is the fix. It's not available through the normal adaptation menu you have to actually cause a misfire on the engine by running it with a loose coil. As you will all know as bad as this rough idle is it's never thrown a code for any of us.

So basically by making the car throw a misfire code it will allow the tech to then run a misfire test module which will open up a menu that allows a particular stratification adaptation reset to be made. It's this adaptation that will allow the tech to change to stratisfied rather than harmoginous and fix this bull shit problem for good.

As I said im booked in next week and will start what I'm hoping will be a new thread to confirm the fix. In the mean time I would all ask to speak to your own master tech regarding the theory and get yourselves booked in.

[335i E92]

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?

You still with us??

[scottp999]

Originally Posted by 335i E92

As I said im booked in next week and will start what I'm hoping will be a new thread to confirm the fix. In the mean time I would all ask to speak to your own master tech regarding the theory and get yourselves booked in.

If you are lucky enough to watch the process, snap some pics of the diagnostic screens.

[335i E92]

Originally Posted by scottp999

If you are lucky enough to watch the process, snap some pics of the diagnostic screens.

Going in on Saturday, will try to get some pic's of the procedure!!

The plugs they put in last were the Bosch one's so I’m having them replaced again with the genuine BMW plugs and getting them to double check the gap's before they do the reset.

Just want to be 100% sure that if the reset doesn’t work it’s definitely not down to the plugs.

Will report back next week.

To the OP, where'd you go? did you find a fix?

[dh5379]

FYI,

I started to have a rough idle and stutter. "Service Engine Soon" light popped up. Had new plugs put in at dealer at 44,000. At 46,000 the rough idle was noticed. Just back from dealer. Diagnostics run and pre-cat oxygen sensor for bank 2 faulty. Will get it replaced next week after part arrives.

David

Originally Posted by AWD Addict

At idle on a warm engine, no fan or A/C, I'm getting a rough idle. A kind of irregular stutter that i can feel in my seat and on the shifter. Even my brother in the passenger seat feels it.

I've had it for a long time, and just thought it was part of hte HPFP issue, but I've had 3 replaced, and I'm currently on the "fixed" one, and i still have it.

At roughly 20k miles, the car went through a 1wk diagnostic with a ton of tests and eventually they took off the valve cover, and the whole valve train was "gummed up" I was supposed to get pictures but never did. They cleaned them out, and the car ran smoother and faster than it had since it was new, and the rough idle went away...


...for a while.

Since then, now approaching 40k miles (and the end of my warranty - when I want this fixed by!) - the stutter is back and as bad as ever. It came on slowly, and gradually. I figured my HPFP was on the outs again, so i took it in again and they said to replace it with the newest version. I've been questioning these last few visits how this problem could be the fuel pump if it's not doing anything after so many tries, but my SA said this was it. No dice. Car still randomly shakes or jerks, or kind of stumbles at a redlight. Needle just keeps hunting for rpms. 800, 650, 400 (jerk) 700.

The car starts with a kind of stumble into idle too (clumsy start), and it stalled about a month ago on me (fully warmed up.)

MY rpms move up and down, irregularly and intermittently sometimes stable with the jerks, sometimes up and down 200-300 rpms.

I'm thinking they should take the valve covers off again, but my SA tells me if they do it, and find nothing, I'm on the hook for a 7hr job.

Thoughts?

[AWD Addict]

Originally Posted by 335i E92

You still with us??

Yes, watching intently as always. Hoping 335i E92 has the answer...

[335i E92]

Originally Posted by dh5379

FYI,

I started to have a rough idle and stutter. "Service Engine Soon" light popped up. Had new plugs put in at dealer at 44,000. At 46,000 the rough idle was noticed. Just back from dealer. Diagnostics run and pre-cat oxygen sensor for bank 2 faulty. Will get it replaced next week after part arrives.

David

Was it showing any codes for the oxygen sensor or was this discovered using some kind of diagnostic test module? The major problem most of us have with this rough idle is that no codes are thrown to indicate the cause.

[335i E92]

Originally Posted by AWD Addict

Yes, watching intently as always. Hoping 335i E92 has the answer...

Lol, I'm 18 months in to this ball ache and wont stop until I've found a fix. I've come too far n replaced to many things to roll over n wave the flag.

The truth is out there!!

[dh5379]

Originally Posted by 335i E92

Was it showing any codes for the oxygen sensor or was this discovered using some kind of diagnostic test module? The major problem most of us have with this rough idle is that no codes are thrown to indicate the cause.

BMW dealership ran the diagnostics and the "Service Engine Soon" was tripped by the bank 2 pre-cat O2 sensor fault code.

David

[dh5379]

The service advisor commented that the service life for the O2 sensor was 90,000 mls. if I remember correctly.

[AWD Addict]

I'm nearing the end of my warranty, so I'm going to try and take one more crack at this. My SA has been great so at least I know they're on my side.

As soon as I'm out of warranty, I'll probably start modding, so this is it. Maybe the Cobb will fix it.

[Armito]

Recently had engine light come up and it was diagnosed that I had lazy (Faulty) O2 sensors in Bank 1 and 2. Dealer wanted $1100 to replace but I bought the sensors from tischer and had them installed at a indy shop for $50.

Before I changed the o2 sensors the car would surge and run rough at idle. One morning it was stuttering so bad that I shut the car off thinking something was wrong, went away after i restarted. With the installation of the new sensors and initialization of the lambda adaption the car feels better then ever.

Not sure if this is the issue you guys are having but in my case the errors did show up with a scan from my BT tool. I dont remember the exact codes but 3 were related with O2 sensor and I had a misfire code on every cylinder pop up the morning it stuttered bad.

[AWD Addict]

Whens' your appointment 335i E92? I'm going in this Friday.

[335i E92]

Originally Posted by AWD Addict

Whens' your appointment 335i E92? I'm going in this Friday.

Going in on Sat, will report back over the w'end!!

[AWD Addict]

Ok. Same here. Are you going to mention the misfire menu bit above? I have a great relationship with my SA, but I'm a bit worried about asking about that.

Given I misfired badly when I tried to pick it up last time, and that's what triggered it again, I may have a good opportunity to do it.

[335i E92]

Originally Posted by AWD Addict

Ok. Same here. Are you going to mention the misfire menu bit above? I have a great relationship with my SA, but I'm a bit worried about asking about that.

Given I misfired badly when I tried to pick it up last time, and that's what triggered it again, I may have a good opportunity to do it.

That's the whole reason I'm going in, the master tech that came out to my local Indy to help diagnose the idle issue advised this reset and I'm going to see him at the main dealer on sat so he can pull a coil n go through the miss fire test module and then reset the special adaptation.

Definatley ask your tech to do it!!

[AWD Addict]

Just talked to my tech. They've found my valve system is pretty gummed up again (see first post), and they're waiting on BWMUSA to approve the full job, which is apparently one that requires their approval due to the billing size. The last time this happened, the car ran dramatically better, and the rough idle did go away for a time.

They'll also be checking plugs and other ignition parts of the system given how it appears the issue came back after the misfire event I had after my last visit.

My SA talked to the shop foreman, who didn't want to reset adaptation values as described above. He asked to see whatever information I could get from the other tech and take a look to better understand the situation. 335i E92, do you have anything from him that I can share?

They're keeping the car overnight to finish the job tomorrow, so I'll post back and update once she's back in my hands.

[335i E92]

Originally Posted by AWD Addict

Just talked to my tech. They've found my valve system is pretty gummed up again (see first post), and they're waiting on BWMUSA to approve the full job, which is apparently one that requires their approval due to the billing size. The last time this happened, the car ran dramatically better, and the rough idle did go away for a time.

They'll also be checking plugs and other ignition parts of the system given how it appears the issue came back after the misfire event I had after my last visit.

My SA talked to the shop foreman, who didn't want to reset adaptation values as described above. He asked to see whatever information I could get from the other tech and take a look to better understand the situation. 335i E92, do you have anything from him that I can share?

They're keeping the car overnight to finish the job tomorrow, so I'll post back and update once she's back in my hands.

It's not your valves...

I had a FULL engine out head rebuild, they sent the entire head off to be chemically cleaned and decarbed and it still misfired like a pig at idle.

This problem is plugs & adaptation related, I'm going in tomorrow 8.30 to get the gaps on my plugs double checked and then the special adaptation reset. I'll let you know tomorrow if it's our fix or if it's another thing to tick off the list of possibilities.

[335i E92]

Did the reset yesterday.

It's now 50% better, its not hiccuping anywhere near as bad as it was and can definatley sit for longer on idle before jumping up from 600 to 800rpm. The tech said it could take 500 miles to fully adapt.

Ill do that within a couple of weeks, wil report back!!

[AWD Addict]

Originally Posted by 335i E92

It's not your valves...

I had a FULL engine out head rebuild, they sent the entire head off to be chemically cleaned and decarbed and it still misfired like a pig at idle.

This problem is plugs & adaptation related, I'm going in tomorrow 8.30 to get the gaps on my plugs double checked and then the special adaptation reset. I'll let you know tomorrow if it's our fix or if it's another thing to tick off the list of possibilities.

You're right. Got the car back yesterday. Techs performed a littany of tests, which was great, including a leak-down and compression test, all which passed fine.

They did a full de-carb and cleaning of the valves, and while the car is running dramatically better again (as it did when they did this 25k miles ago), I still have the noticable stumble and hiccup. The top end on the highway is honetly like a new car. I didn't even notice how much she was being strangled. I think I'm a lock for a full tune when the warranty expires, as I can only imagine this gummed up valves are a function of the OE de-tuning, which I'm guessing has this thing running pig rich.

I'll wait to see how the adaptation works with you. My SA asked to see what process your tech reccomended, so if it works, is there any way you can get something from him that I can hand to my SA? Even an email would be really helpful.

[mj6234]

I don't really have a rough idle, but under load at around 2500-3000 RPM it feels like I have a miss that happens. It is most noticable in the higher gears, especially when going uphill. I have 32K on the clock and am going to replace the plugs this weekend. I am completely stock. It really feels like 1 cylinder is missing, so I am hoping it is just a plug.

[335i E92]

Originally Posted by AWD Addict

You're right. Got the car back yesterday. Techs performed a littany of tests, which was great, including a leak-down and compression test, all which passed fine.

They did a full de-carb and cleaning of the valves, and while the car is running dramatically better again (as it did when they did this 25k miles ago), I still have the noticable stumble and hiccup. The top end on the highway is honetly like a new car. I didn't even notice how much she was being strangled. I think I'm a lock for a full tune when the warranty expires, as I can only imagine this gummed up valves are a function of the OE de-tuning, which I'm guessing has this thing running pig rich.

I'll wait to see how the adaptation works with you. My SA asked to see what process your tech reccomended, so if it works, is there any way you can get something from him that I can hand to my SA? Even an email would be really helpful.

.

I'm now about a 100 miles since the adaptation reset. It's definitely better but still bad. I'll give it until around 500 - 750 miles and report back, not hopeful to be honest but we'll see.

My car ran better also after the decarb, much smoother & stronger power delivery. I'm booked in on Sat to get my ETS intercooler fitted and my vanos solenoids replaced as i'm getting limp mode and vanos codes when i go full wot. Who knows maybe this will fix...

I'll report back in a couple of weeks.