[ChawenHalo]

GO DOWN TO MY LAST MESSAGE of 12/02/18.

OK so I've got a little further with my bloody 4949 error code.

Here's the history. Bought car: E91 LCI Xdrive 330D 128k km ('bout 80k miles). Idles rough as fe€k after cold starts for a few 30 secs/ 1 min if left alone (or until I give it more revs a few times) then OK until next day. Uses too much devil fuel too (8L/100 km or 34 MPG)

I start by only feeding it "premium" diesel (I only do long journeys) and it starts less rough and consumption starts to go down.
Got Intake and EGR cleaned. Uses less fuel. (7.2L / 100km or 39 MPG) -
Changed glow plugs (2 faulty) and 2 stuck 1 specialist latter all changed but 1 error code won't go away. Still "misfires" in the morning

Got preheating module changed. Still same problem and same error coide 4949 glow system configuration.

In desperation I book it in with BMW for a system re-initialisation / system sofware update. And feed it snake oïl. Now uses more fuel once again.

Anyway chez BMW, very helpful little outlet tech guy tells me there are no error codes but will update eveything anyway. He also tells me that its more likely to be injectors. After the update, he now finds that Frigg)n€ 4949 code and that tells him that he ought to change the preheating module. Says he'll use the parts warranty for a new one but that he still believes that the symptoms have nothing to do with it.

He also checks everything with FAP and all is perfect on that front.

I need to leave the car with them for a couple iof days so that they can start it from cold and have it plugged it to the diagnostic bench.

Now the update has not done it any harm. Consumption has gone back down and it seems to boost better and more smoothly. Will see how she starts tomorrow...

Any ideas fellas? I though injector problems where quite distinct and included somking problems, holes in torque Delivery/ acceleration, rough running etc. Mine runs fairly sweet tbh apart from whan left alone for say 6hrs +

Could do with some insight here please...

[Andy198712]

i know on the audi 3.0tdi engine worn injectors will show they're self as very smokey if left idling for long periods of time.... not something people normally test though in day to day driving!

[old grey steve]

Seen a fair few of these engines of late rough idle could be the glow plug controller(usually shows up as a plausibility reading and the controller seems to be more the likely candidate than the plugs themselves-though it doesn't hurt to change these though unlike the M57 these plugs are more prone to be stuck fast in the head) but more common and dare I say it more alarming is the amount of issues we have seen re the intake manifold itself.

Swirl flap plausibility is something I've seen on diagnostic many times re these engines(remember the N57 is a different beast to the M57)but when removed and I've got from memory a good 5-6 duff manifolds lying around with different degrees of contamination/failure it is to my eyes not good news overall that these symptoms appear to be happening with these manifolds(see below) we've even had cars with idling issue that exhibit when scanned no faults(we use the genuine BMW diagnostic as well as AutoLogic to scan) and in at least 2 cases we have replaced the manifold started from cold and the issue is resolved.






Common issue are or appear to be upon start up a rough idle, sometimes reported as a tremor through the car (if you open the drives door place your hand on the frame you can feel the slight unevenness) that settles down after a minute to 2 minutes or so and when pulling away a general or slight lethargic response is reported.

In cases we've had post manifold change(along with where rquired due to contamination the EGR pipe) the difference is night and day

Lowest mileage I have seen with a manifold related issue is 39k, tough one to call the manifold isn't cheap £700+VAT over here the relay is £106.85+VAT but these 2 items do come up far too often to be ignored but if i were a betting man I'd say manifold

[Andy198712]

So is it the manifold or the swirl flaps creating the issues do you think? Just wondering if the OP had no luck and was thinking manifold he could try removing the flaps first (a lot cheaper) ?

[old grey steve]

Originally Posted by Andy198712

So is it the manifold or the swirl flaps creating the issues do you think? Just wondering if the OP had no luck and was thinking manifold he could try removing the flaps first (a lot cheaper) ?

Difficult to say the swirl flap set up is wholly different to that of he M57 where we knew where we stood and the issue was straightforward to sort (before it caused mayhem)but this is a different beast, seen a few attempts to remove the swirl flaps only to see various faults reported, but the manifold design is totally different I'm thinking tremendous heat for instance plus the usually crap that gets forced through these manifolds is a concern, honest answer is I can't say the only thing I can say is I've seen more than enough to understand I'll see a lot more due to the design

[Len_Beach]

I removed my swirl flaps and the car definitely ran better afterwards.

I was seeing swirl flap plausibility codes which is a sign the flaps are not fully closing due to carbon build up.

I fitted a fully cleaned and de-flapped manifold and saw the same errors. I now suspect the actuator is faulty and I'm picking the car up today after some work including a new actuator. Madness I know given there are no flaps to actuate but the faults bug me like mad.

Try source a second hand manifold, deflap it and clean it. Once the flaps are gone there's little else to go wrong other than the manifold cracking.

[ChawenHalo]

Originally Posted by old grey steve

Difficult to say the swirl flap set up is wholly different to that of he M57 where we knew where we stood and the issue was straightforward to sort (before it caused mayhem)but this is a different beast, seen a few attempts to remove the swirl flaps only to see various faults reported, but the manifold design is totally different I'm thinking tremendous heat for instance plus the usually crap that gets forced through these manifolds is a concern, honest answer is I can't say the only thing I can say is I've seen more than enough to understand I'll see a lot more due to the design

Thanks Old Grey Steve. I did indeed see some your posts on the subject. On my froggy forum some guys rekon that when changing the plugs, cleaning the EGR and intake manifold its vital to also change all the seals - at least 2 or 3 guys have reported a marked improvement or total recovery. Likewise on sofware updates, some of which had changed plugs and modules.

I'm a little skeptical but neither am I sufficiently mechanically minded to know whether the intake manifolds functions airtight. When you take these off for replacement what is the actual problem with them?

For a bit of an update. Since the new software yesterday, the car does drive much keener. It was not bad before but hear it seems to pick up much earlier lower down the revs. strangely enough I seem to hear the turbo more... (I hope that's not Something to worry about) And joys of joys, this morning some tractor like noises (I've been driving exclusively inline 6 petrols in the last 5 yrs - so this really is the devils fuel) but a smooth idle. I think its a little too early to call it sucess so will report back.

[ChawenHalo]

Originally Posted by Len_Beach

I removed my swirl flaps and the car definitely ran better afterwards.

I was seeing swirl flap plausibility codes which is a sign the flaps are not fully closing due to carbon build up.

I fitted a fully cleaned and de-flapped manifold and saw the same errors. I now suspect the actuator is faulty and I'm picking the car up today after some work including a new actuator. Madness I know given there are no flaps to actuate but the faults bug me like mad.

Try source a second hand manifold, deflap it and clean it. Once the flaps are gone there's little else to go wrong other than the manifold cracking.

Only error I get is 4949 which is glow system configuration. BMW tech says that means to change the preheating module. Given that's already been done he says it could be a duff one and will work the parts guaranty to replace it.

Got to say, my wife old Z3 2.8 coupe does not half have the issues these modern diesels have. Right old tank (the car not the wife obviously )

[Mboon]

My N57 325d rough idle and is resistant to pull away for a few minutes from cold. Perfect when warm. It does blow a little bit of smoke on start-up (it's done 170k). Error code I got was for the air intake sensor. I also took the covers off the engine and found some damp around the two front injectors. I am hoping it's just blow back and just needs sealing again

[ChawenHalo]

Well its definately better after start up from cold but not 100%. Its also starting to feel like there are holes in the acceleration when accelerating lightly. My money is on injectors issue. MBoon, what this about blowback? (To me blowback involved a Young pretty lass and Something illegal when I was young ))

[ChawenHalo]

Someone else with the same prob?

Links to original thread:
http://www.e90post.com/forums/showth...4#post21936174

[Mboon]

Blow back is when the seals on the top of the injector are not doing there job. Removing the injector and replacing the seal can solve the injector leaking on the top causing rough running when cold. I have two injectors that are damp on top

[ChawenHalo]

Originally Posted by Mboon

Blow back is when the seals on the top of the injector are not doing there job. Removing the injector and replacing the seal can solve the injector leaking on the top causing rough running when cold. I have two injectors that are damp on top

OK I'll post some picks. It would be nice if it could just be that!

[Kuroblack]

Not sure if it's relevant but I had some trouble around 40K with my 330d and a rough idle on start up. Occasionally it felt like it was about to stall when I selected either D or R - really odd, also it felt hesitant on very light throttle inputs...

I had the EGR changed under warranty to no avail, then had some EGR coolant part swapped (may be been leaking, not sure) which cleared it up instantly.

As I say, probably not relevant but the rough idle and hesitancy were certainly there for me, actually I think I had a youtube video linked from a post on here at some point.

[ChawenHalo]

Originally Posted by Kuroblack

Not sure if it's relevant but I had some trouble around 40K with my 330d and a rough idle on start up. Occasionally it felt like it was about to stall when I selected either D or R - really odd, also it felt hesitant on very light throttle inputs...

I had the EGR changed under warranty to no avail, then had some EGR coolant part swapped (may be been leaking, not sure) which cleared it up instantly.

As I say, probably not relevant but the rough idle and hesitancy were certainly there for me, actually I think I had a youtube video linked from a post on here at some point.

Thanks Kuroblack.

EGR valve and cooler are indeed often listed as part of cause of these faults.

Was this on an N57 engine?

Just to report back on mine, so far so good. Changes are not 100% but in the last few days the idle is stable fter start up. I strongly suspect though that its far from over and would point towards injector issues or EGR or intake seals.

Will report back when I'll give it to BMW for a few days (after the holidays).

[AzRiz]

I had the rough idle and near-cut-outs on cold starts for a good while. It got far worse after the car came back from spending a few weeks at a bodyshop.

Errors showed EGR valve issues.

I had EGR changed out, as well as glowplugs and glowplug controller. EGR was stuck in the open position, IIRC.

Since the change, all good again, it was 99% likely the EGR valve which had got coked up due to too many cold starts with no drives by the damn bodyshop.

2010 N57 330D, about 72k miles at the time of this work, does almost solely motorway mileage.

[Mboon]

Can the EGR be blanked like on the M57?

[ChawenHalo]

Originally Posted by Mboon

Can the EGR be blanked like on the M57?

Don't think so not that easily and without getting a raft of warning lights and problems. TBH on the N57 the EGR valve does not get sooted up like on the older engine. Its in a different position.

[E60525d]

Any luck on this, did you manage to solve it?

[ChawenHalo]

Originally Posted by E60525d

Any luck on this, did you manage to solve it?

No not yet, just got the boot from work so it will wait next month. I did however have an interesting experience:

Since I've bought the car 4 months ago I only fill it with premium (Exellium or whatever) diesel from Total (its pretty much 80% of all stations in my region). Before the hols I had to fill it with supermarket diesel and although on the motorway back from work it felt OK (I thought great its a bit of a save) the next day it was rough. It gradually got rougher whenever I would restart the car and actually stink.

Now back to premium juice and its back to its "normal" rough idle, in just 1/2 tank full. Definatly thinking this is injection related, but then I'm no mechanic and I don't understand why then its fine on full throttle and top speed. If anything it does seem to hesitate sometimes with just a little jolt, usually going from no throttle changing gear to low/ mid throttle application. Does not do it when warm though.

The car's guaranty ran out when I bought the car so might try to cry at BMW Frogland (real misers). If I new it was something simple like seal or whatever I'd give it to my local but I've so far replaced and done too much work and expense trying to self diagnose (EGR and intake clean, glow plugs and controller, sofware update at BMW) with very little result.

If anyone has any pointers regarding bad injectors on a N57 it would be useful. I'just not yet seen on any forum injector issues on these engines...

[Mboon]

I was using supermarket fuel in mine and decided to put some supreme plus rasp and redex in the tank. Completed a 120 mile motorway journey and it improved. It completed cured it on one start and then came back but not as bad

[Len_Beach]

If you suspect it's injectors, have you tried a fuel additive like Archoil AR6400-D Max.

I know they get mixed reviews but it's a cheap option that may give some gains.