N52 engine problems - sh*tloads of smoke, hesitation - HELP!

[a11y]

Hopefully you lot wont mind as technically this is my e90 330i, but it's the exact same N52 3000cc engine as in facelift e85/86s so hoping others on here might be able to shed some light on my problems.

Last weekend (on the way home from hospital after the birth of my daughter, of all the bad times for it to happen...) I got a LOT of grey/black smoke from the exhaust under hard acceleration, with the smoke continuing after lifting off. Smoke also present on start up from cold and from warm. And we're talking a LOT of smoke: enough to totally obscure the car you've just overtaken . Oil level is fine, coolant level perfect, nothing untoward under the oil filler cap. Lots of black bits on the rear of the car (like the particles you'd get from a diesel) and exhaust itself is very black. Performance is reduced - just doesn't feel like full power, with the occasional stutter/misfire. I've tried a treatment of Redex injector cleaner but no difference.

This morning I took it to a recommended auto electrician/mechanic. No codes were brought up on the fault reader initially. Mechanic took it from a drive with me in the car - after hard acceleration off a roundabout his exact words were, "Oh ya f**ker* as he looked at the amount of smoke behind the car...

Got back to garage, disconnected the MAF sensor (aka air flow meter) and went for another drive: no smoke whatsoever and decent - although possibly not full - performance. Stopped in a layby, reconnected the MAF sensor, and as soon as we drove off an engine management light came on, smoke reappeared from the exhaust, and the car was incredibly hesitant and running poorly. Fault reader diagnosed a problem with combustion in cylinder 5, no other fault codes reported.

We're all a bit unsure where to start so looking for ideas/opinions...

It's definitely running rich - burning too much fuel.
Injector(s)?
O2 sensor(s)?

Initially he's going to replace the MAF sensor for starters, but if that doesn't solve it does anyone have any good/sensible suggestions?

Cheers,
Ally

 

[srhutch]

What about a coil pack?

 

[bigdog]

First, Congratulations. All the best to your family.
I'm with srhutch. I would think at the least the coil pack is kaput. I fear that it's more than that as a bad coil pack shouldn't start working after a maf disconnect. Surely hope that it's not too costly to fix.

 

[a11y]

Cheers. Not quite sure what a coil pack is so I'll get researching - do my symptoms point towards this?

Car is currently left with the garage with them intending to fit a new MAF sensor to begin with. Fingers crossed it'll be a simple/quick fix as I want it back.

And cheer bigdog

 

[pvr]

I replaced a coil pack on a VW, it ran like a dog with the problem pack. Feels like it is running on one cylinder less, very noticeable and almost stalling when on idle.

Is your idling ok?

 

[slick]

Standard air filter or K&N ?

 

[bigdog]

Cheers. Not quite sure what a coil pack is so I'll get researching - do my symptoms point towards this?

Car is currently left with the garage with them intending to fit a new MAF sensor to begin with. Fingers crossed it'll be a simple/quick fix as I want it back.

And cheer bigdog

The coil pack is just a step up transformer. It takes the 12 volt ignition pulse and ramps it up into the Kv range. In new cars they sit right on top of each spark plug. On your van. the coil would have a single high tension lead going to the center of the distributor to be sent to the plugs via other HT leads. Of course that assumes your Vee Dub is old enough to have that old system.

 

[a11y]

I replaced a coil pack on a VW, it ran like a dog with the problem pack. Feels like it is running on one cylinder less, very noticeable and almost stalling when on idle.

Is your idling ok?

Idling perfectly, and revving fine too, Well, it was until we unplugged the MAF sensor then reattached it - it idled and revved like a bag of spanner thereafter.

Standard air filter or K&N ?

Standard - car mechanically standard.

TBH I'm still no clearer on a solution but I've left it with a mechanic I trust so we'll see what he finds after replacing the MAF. I suspect there'll still be an issue with combustion in one of the cylinders (as indicated on the fault reader) in which case I'll see what he suggests...

 

[mr wilks]

when i dropped a coil pack on a previous car it ran lumpy but no smoke was noticeable .
if the fault code pointed to one specific cylinder could it not be a faulty injector ?

 

[a11y]

when i dropped a coil pack on a previous car it ran lumpy but no smoke was noticeable .
if the fault code pointed to one specific cylinder could it not be a faulty injector ?

TBH that's what I've been thinking all along - the newer N53 engine (with direct injection) suffers from a lot more injector issues but I've not heard about issues with N52 injectors. From my limited mechanical knowledge, the symptoms seem to fit with what I imagine a knackered injector would result in.

 

[Ewazix]

Once you've replaced the MAF and eliminated the coil packs check the crankcase breathers which can cause similar problems on many units inc BMW.

However I had similar symptoms on a non-BMW unit using a similar set-up (MR2) it turned out to be un-metered air getting in to the the intake tract throwing the MAF sensors and fuel mixtures right off, have a very careful check around the vac pipes, hoses and fittings on the the air box and inlet tracts, unfortunately it only takes a tiny leak. I haven't tried it but you can apparently spray intake cleaner around the pipes and joints, if the engine runs differently (probably worse) then you are in the right area.

Let us know how you get on :|

 

[Ewazix]

May be of interest, don't underestimate problems than can be caused by blocked oil breather separator systems, I've had it on other motors but not like THIS

http://www.youtube.com/watch?v=b2ckWl4xoxI

and the maintenance

http://blog.bavauto.com/5434/bmw-m54-6-cylinder-crankcase-ventilation-pcv-diy-325i-328i-330i-525i-530i/

 

[a11y]

Cheers.

Mechanic has been in touch with BMW dealer for 2nd opinion. Apparently there’s no MAF on the car lol so it’s not that – TBH I’m hearing this info 2nd hand from my father-in-law (the garage/mechanic is good friends with him) so unsure exactly what was said. They suspect either crankcase breather blockage or valve stem oil seals being knackered, but I’m not so sure as the oil level seemed fine. Not sure if that’d be reflected in excess unburnt fuel instead…

 

[Daffy]

Ally, I thought your E90 was a 57 plate?

 

[a11y]

Ally, I thought your E90 was a 57 plate?

It is: 57-plate 258ps N52 3.0i. At some point soon after my build date they changed over to the N53-engine with 272ps (direct injection and efficient dynamics), but that was sometime in later-built 57-plates/08-plates.

Is there something that I've posted that doesn't match that? I mean mechanically, etc. Just in case the garage/BMW is barking up the wrong tree...

 

[Daffy]

No, not at all. I was just certain that I'd seen it as a 57 plate a knew that 57+ were N53s and had injector problems...

Apologies.

 

[a11y]

No, not at all. I was just certain that I'd seen it as a 57 plate a knew that 57+ were N53s and had injector problems...

Yeah the changeover date from N52 to N53 is very unclear! I was glad my budget didn't stretch to an N53 given their injector issues but it seems I'm just being unlucky with mine...

First pics I posted of the car were before my ALY plate was added, so top marks for remembering

 

[Newbers]

If there is no MAF - what did the mechanic disconnect?

If you've got a lot of smoke surely thats going to be oil rather than fuel related?

 

[a11y]

If there is no MAF - what did the mechanic disconnect?

If you've got a lot of smoke surely thats going to be oil rather than fuel related?

It was a sensor/connector into the rear of the airbox. And I just don't think it's oil-related (I could be, and often am, wrong) as the oil level hasn't dipped in the slightest.

Well, my car got dropped off at my house last night (that's service!). Garage spent last weekend the garage disconnected various electrical connectors, cleaned things up if they looked like they needed it, then reconnected them. Since doing all that they’ve been unable to replicate the symptoms. Car is apparently now running perfectly: no smoke, no stuttering, pulling strongly, no fault lights, no fault codes. Weird. Just about to head out for a drive and give it a bit of stick to see how it goes.

Mechanic had spoken to BMW about it who had made the suggestions of valve stem oil seal or crankcase breather, but he doesn’t believe either of those due to oil level being fine. I’ve just to drive it and see if it happens again and take it from there.

Part of me wonders if washing under the bonnet a few months ago was a good idea lol: http://www.flickr.com/photos/a11y_m/7970073120/ - all I used was a very very very low pressure water sprayer and some cleaner, but I wonder if water go in somewhere it shouldn’t have…

 

[ZermattV]

Hope it's on the mend A11y