[Hunty93]

Hi Everyone,


I have just brought my first BMW so I'm very new here, five minutes of driving and I have got the BMW bug.

Car Details:
2011 E91 Touring with N43 Engine

After being extremely over the moon with her, I believe I was caught out by the previous owner warming her up for the viewing.

I'm going around in circles with this misfire, one cold starts she has a very rough idle - starting at around 1000rpm after a few seconds she bounces around 700rpm; this is when the misfire is very apparent. after around 30 seconds of idling the engine management light will start to flash, then vanish and come back after another 30 seconds. if I let her idle for a while the engine management light will stay on. Turn the engine off and start her up again, no engine management lights but still rough.

Codes That Have Come Up:
Cylinder 2 Misfire (Always Comes Up)
Cylinder 3 Misfire (Comes Up every So often)
Bank 2 Running Rich (This was always with Cylinder 2, hasn't happened recently )

Things We Have Done:
New Sparks
New Coils
New Injector Number 2 (Index 11)
Engine Carbon Clean
After Engine Carbon Clean we decoked the intake valves
Vanos Sensors Cleaned (no real blockages, fairly clean actually)

After the ECC bloke left I took her for a spin, notable performance increase but this could of been a placebo effect. but when i put my foot down Id be held back by the engine management light (Cylinder 2 & 3 misfire).

After the decoking the intake valves we changed the injector, she sounded and felt a bit better which felt promising as everything else we did she felt worse. I took her for a blast up the A41 after the injectors, stopped at the services to let her idle for a bit - Low Oil Pressure Light comes on, after leaving engine off for a while the light disappears and doesn't come back unless i go for a drive and let her idle again.

Currently as I write this I'm waiting for a new O2 sensor for bank 2 to turn up as O2 bank 1 fluctuating at .45V and bank 2 stuck on 1.19v, no movement what so ever and the fact that it only ever misfire on 2&3 which is O2 sensor bank 2. I'm kinda preempting it not to work after this I'm truly stumped, hence why I'm posting this.

[Hunty93]

Update: O2 sensor didn't make a difference.

[frenchi]

These engines always ask for 4 new injectors,replacing just one doesn't cure the misfires as Dme try to compensate.

[AndyVR]

I have very similar problems with my 2010 N43, cylinder 2 misfire & 29E1 (Fuel mixture control 2) Do you know what fault code you got for 'Bank 2 Running Rich' ?

When you say 'Engine management light' do you mean the yellow 'increased emissions' warning light?

I only get the emissions light if I leave it idling, if I raise the revs or drive straight away I can avoid it coming on (obv. not a permanent solution!)

I've recently replaced all other ignition coils & spark plugs, seemed to of cured my rough cold idle but this morning detected a slight misfire/lumpiness again, after 10 seconds or so. I've had this problem almost a year (worse in winter) yet I still get about 35mpg, what are you getting?

Was the new injector registered with the DME? how good is your garage/tech?

Could there be a wiring fault to one or more of your ignition coils - or a bad earth?

Also swop plug & coil 2 with say cyl 1 or 4, to eliminate your recent new plug being damaged by overfuelling at some point.

Hope you get it sorted.

[Hunty93]

I've got the same code as you on Bank 2.

I've only had the vehicle for around 2/3 weeks, I've always known it to be an engine management light but after googling it is the increased emissions light.

I've always let her idle before driving until the other day, the light didn't come on but i could tell for first mile it was very lumpy.

The injector is getting coded hopefully tonight as my tech (very close family friend) owns his own garage I've got to try and slip my self in a quiet period to get it done as i don't want to seem like I'm taking the piss. Hopefully his machine can highlight something as my simple code reader only shows a code if a warning light pops up. I think ill change the coils over tonight after coding.

All the wiring and earth seems okay. I'm starting to get concerned about the oil pressure light as I'm now thinking timing chain. But after a oil change and putting a endoscope in the sump I couldn't see any plastic there as I know the plastic runs snap - doesn't prove that the chains not knackered I know.

If not that, DME update? but I've had a quote from BMW that is close to £1000.

After doing an oil change I had a yellow car on a lift - I've in the book that its linked to brake lamps or fuel supply malfunction. Vanished once I restarted the car.

The joke is once shes warm and running she seems fine, but I'm just concerned I'm doing more damage.

[AndyVR]

What mileage is yours at?

Also check/replace the oil cap- some swear by these being faulty and affecting running by leaking air/vacuum.

Did you get your injector coded?

Mine has a new fault - hesitation/judder/stutter under acceleration at low speeds, cold or warm, no emissions light. Previously with it's misfires & emissions light on etc. it would still accelerate smoothly, so I don't know what's going on now (unless it's been caused by the new plugs/coils that I fitted a few days earlier, I could have a dud coil I guess?) I need to check the codes again. Maybe one of the injectors (no.2) is getting worse.

I also have the same issue with low oil pressure warning at hot idle, it started after I'd owned the car for a couple of months. Used to only occur after a really long run, but now 15 min drive to work and the warning can come on as I pull into a parking space. Doesn't occur when the idle is held a little higher, and some weeks it wont do it at all. Plan is to replace the oil and filter with the correct LL04 oil & genuine filter (I don't know what's in there currently) sounds like you've done that already.
That's a good idea using an endoscope to look in the sump for oil pickup blockages, I might try the same, didn't fancy taking the sump off just yet.

[david in germany]

BMW did a recall on the N43 engines for bad injectors. My 118i had the same issues and the misfire on cylinder 1. I had them change out all the injectors prior to the recall and then they did them all again with the updated injector during the recall. My issues are all gone.

[Hunty93]

Oil light seems to have sorted itself out now, fingers crossed on that one.

Hand the injector coded, no joys, everyone is saying replace all injectors as it's not necessarily the injector on the cylinder that misfire at fault. I find this a bit hard to believe, mainly because I don't want to spend all that money and for it to still misfire.

Sometime this week I'm going to pull the injectors out and just and seals and o rings, try and pull back to basics.

180k on the clock, all motorway miles on one previous owner.

I did read somewhere that the MAF sensor caused someone hesitation, but I only skimmed that post as I was hunting for misfire issues.


Oh and I found out the heater doesn't work now, one thing after another with this thing. I knew the air con didn't work but I expected the heaters to work.

[AndyVR]

Originally Posted by david in germany

BMW did a recall on the N43 engines for bad injectors. My 118i had the same issues and the misfire on cylinder 1. I had them change out all the injectors prior to the recall and then they did them all again with the updated injector during the recall. My issues are all gone.

They did but only for earlier years, can't remember which years were covered but unlikely the OP's 2011 car was covered as it would of have revised injectors from new.

[AndyVR]

Crap isn't it. I'm not convinced about 'replacing all injectors' either, this could be misinformation from the earlier models that had injectors that couldn't be mixed with the new revised ones.

I will get some MAF cleaner and try that.

MOT time tomorrow, hope it will pass and not have a random misfire or DSC episode on the brake rollers!

hope the heater is an easy fix.

[Dormermike]

Have you reset all ecu adaptations as well as coding the new injector? Might be worth a try.

[Hunty93]

Misfire Fixed!

Replaced all injectors, turns out the misfire detection is shit on these engines (openly admited by BMW Technical). As soon as I fired her up you could feel the difference.
Started this morning runs perfect, even considering how cold it was!

Oil Pressure light has made an appearance and the journey to get the injectors coded which ruined the mood I was in as I thought I had come to the end on the struggles.

Hopefully Ill get the oil pressure switch out today and give it a once over, hope i wont see and plastic in it!

Andy - Did you get your hesitation sorted?

[david in germany]

Yep, first sign of a leaky injector is rough cold starts. Glad you found the issue!

[AndyVR]

Glad you got your running issues sorted.

Handy to know that about the random misfire detection, I've only got one injector on order so fingers crossed it's telling me the right cylinder!

Not got anywhere with hesitation yet, I've got MAF cleaner and a new revised oil filler cap to try, will be checking for intake air leaks/splits this weekend.

It passed MOT ok the other day on emissions, then on the way home threw the engine/emissions light and was running on 3 - it's never done that before when warm so injector(s) must be getting worse.

Is your oil pressure light coming on at idle or when driving? let us know how you get on. Found a good tech article on N43 oil pressure here https://autologic.com/news/blog/friday-fault-2-fix-55

btw, did you fit new decoupling elements (the metal ring/hook type thing) to your injectors or reuse the old ones?

[Hunty93]

Have you checked your VANOS solenoids yet? They tend blocked up and can cause hesitation.

I thought I had fixed the oil pressure light issue by changing the the oil pressure valve, but then came on after a 10 minute drive. The light will only come on after I?ve finished driving or at traffic light when I stop and idle for a few seconds.

I see you?ve change the oil filler cap and I?ve read they cause problems with oil pressure - reason I say this was my mate flip the seal in the cap when working on the car and mention these have issue, light has only come on since then. The amount I?ve driven the car before that point wasn?t a lot so it hard to say.

[Hunty93]

I cleaned and reused the couplers, I did have an oh fuck moment when changing them as I forgot to grab them.

Luckily I got away with reusing.

[AndyVR]

Not checked Vanos solenoids yet, need to add that to the list.

Take it you didn't find bits of plastic in the pressure valve? I'd get the oil pressure checked with a workshop gauge, cold and then hot, see if it's within limits. Could possibly be a dodgy oil pressure switch.

What oil/viscosity are you using?

I've not even fitted my new oil cap yet!

[AndyVR]

Originally Posted by Hunty93

.

I got lucky - changed Cyl. 2 injector a few weeks back, misfire issue solved. This morning clarified it for me as it was 0 degrees outside, and the car idled perfectly while I de-iced the windows, I've never been able to do that without the idle dropping and running on 3 cylinders.
[EDIT - Didn't get lucky, misfire back same as before, same Cyl 2 misfire & bank 2 mixture codes !!!]

I also seemed of cured the low oil pressure warning at Idle - this has been fine since changing the oil (Shell 5w/30 LL04) and fitting a Genuine BMW filter about a month ago.

The old filter was a decent MAN filter - but it didn't have the rubber seals at the ends of the filter bore like the Genuine one does, it just had a thin 'tape' or plastic coating - SO the genuine filter is a few millimetres longer than the Mann one, I have my suspicions that some aftermarket filters are letting oil seep past between the inside and outside of the filter - causing a reduction in oil pressure.

[Chadlar]

Sorry to post a year later, but did you get the misfire issue resolved. I have just purchased a E91 BMW 320i M sport and seem to be having a similar issue, cylinder 1, sometimes 3, misfire with the bank 2 code. Mine misfires whilst the engine is cold at around 3000 rpm. Once the engine is warmed up its sweet as a nut.

Did you have to replace all injectors?

It's really annoying to be constantly told how nice my car is (even by the garage) to then have to drive knowing I've got this problem!

[AndyVR]

Originally Posted by Chadlar

Sorry to post a year later, but did you get the misfire issue resolved. I have just purchased a E91 BMW 320i M sport and seem to be having a similar issue, cylinder 1, sometimes 3, misfire with the bank 2 code. Mine misfires whilst the engine is cold at around 3000 rpm. Once the engine is warmed up its sweet as a nut.

Did you have to replace all injectors?

It's really annoying to be constantly told how nice my car is (even by the garage) to then have to drive knowing I've got this problem!

So you've got misfires across both banks. First port of call is to pull the plugs and check condition - probably replace. Check the ignition coils for any oil or arcing (they should be clean and dry) you could mark the coils with the cylinder number they came from and swop them about, to see if the misfire moves to a different cylinder. Possibly then replace ignition coil(s) on affected cylinders before looking at injectors.

[dkimigz@gmail.com]

So for me, after months of chasing this, I came to find out it was one of the Oxygen Sensors (Bank 2). I bought and installed it, and the car (BMW e90 LCI, N43) became brand new. How did I know? So the codes were telling me lambda bank 2 before O2 sensor. But I still ignored this (I blame the mechanic). I bought 4 new coils, spark plugs, two injectors and a battery, but still, there were random misfires across cylinders. I hope this helps someone one day.

[mjo3sBMW]

Originally Posted by dkimigz@gmail.com

So for me, after months of chasing this, I came to find out it was one of the Oxygen Sensors (Bank 2). I bought and installed it, and the car (BMW e90 LCI, N43) became brand new. How did I know? So the codes were telling me lambda bank 2 before O2 sensor. But I still ignored this (I blame the mechanic). I bought 4 new coils, spark plugs, two injectors and a battery, but still, there were random misfires across cylinders. I hope this helps someone one day.

Nice, hope this will do the trick for me too. I'm having misfire on Cylinder 3 and replaced 4 plugs already. No. 3 plug was showing some wear and burnt in it.