[E92JMT]

Hi everyone, I have a 2008 E92 320i (170) m sport.
As the title says it's just failed it's MOT on Emissions, here is the readout:

FAST IDLE TEST
Engine speed =2495
CO =3.42%. FAIL (Max 0.20)
HC =200
Lambda =0.901

SECOND FAST IDLE TEST
Engine speed =2350
CO =2.74%. FAIL (max 0.20)
HC =201 FAIL (max 200)
Lambda =0.920

NATURAL IDLE TEST
engine speed =700
CO =0.20

OVERALL RESULT FAIL


Can anybody make sense of this or point me in the right direction, he said I may need to take it to BMW for a proper diagnostics test.

He did tell me something about a fault code (12522) but this means nothing to me and I can't find it online.

Any help would be great!!

[Thermobaric]

Take it to an indy. They'll scan for codes and find the cause. Should be cheaper than BMW.

[Dann]

Give it a good hoon taking the car up to red line in different gears several times when the engine is hot. That should help clear the cats out.

It could also need new lambda sensors.

My E36 failed emissions so 2 new lamdbas, a few hot redlines and a stretch of motorway driving in 419th hear made it pass.

[old grey steve]

Without seeing the car its difficult but I'd start looking for a possible air leak, adjuster valve fault and the breather system of the vehicle and move from there but with these cars you can as I've got one here look at all sorts of things that can cause issues, depends on of course whether we are looking at an N43N46 as for instance the N46 requires a rocker cover replacement as the breathers integral but these cars can tie you in knots if you don't know where to look

[Dormermike]

Air filter ?

[E92JMT]

Thanks guys, it also seems important to mention that the car hasn't really had a good run in a while as Ive been getting the bus to work.. It's been sat up for a few days before the MOT and I'm only really driving it short distances once or twice a week. Could this maybe be the issue? I'll try giving it a good trashing!

[Dormermike]

Is this a direct injection engine ?

[ed330D]

I may be remembering this completely wrong, but some direct injection engines are supposed to have the readings you are getting, i.e. there may be nothing wrong with your car.

If you have a lean burn engine the readings are supposed to be much higher. Have a read of:

http://www.e90post.com/forums/showthread.php?t=769965

[E92JMT]

My lambda was in spec though, and it said lambda max was 4.0. As for my CO and HC values, I'm not sure

[E92JMT]

Originally Posted by Dormermike

Is this a direct injection engine ?

Yes I believe so, I have the N46 I think which is direct injection. It's the 170bhp

[old grey steve]

Originally Posted by ed330D

I may be remembering this completely wrong, but some direct injection engines are supposed to have the readings you are getting, i.e. there may be nothing wrong with your car.

If you have a lean burn engine the readings are supposed to be much higher. Have a read of:

http://www.e90post.com/forums/showthread.php?t=769965

Kind of a fair point, the other issue can be actually something quite important and we see a fair bit of this:

Has the correct car been tested what I mean is on some cars there are multiple choices of say X model input the wrong info before test you could well see your kerb weight as well as the all important emmission detail you have on the car in front of you differ from that of the required test standard and trust me seen a fair few through our doors re BMW's as well as Merc' thing is it's actually if your not alert not that hard to input the wrong car into the system or it was until the latest on line roll out was introduced late last year.

But on OP's car so so difficult to say but emmission issues can be down to a number of things lack of use could play a small part but on these engines seen a fair few with multiple issues as I said earlier depending on whether the cars got an N43 or an N46 will effect somewhat the potentual complexity re what could be 'a potential cause'

[E92JMT]

I'm going to give it a good run before the next MOT. I will update the results

[Aragorn30d]

His results arent lean, they're rich. Lambda is below 1.

Theres clearly some fault with the engine.

[old grey steve]

Originally Posted by Aragorn30d

His results arent lean, they're rich. Lambda is below 1.

Theres clearly some fault with the engine.

With these cars emmission issues aren't uncommon and as I said on an earlier post they can tie you in knots, like you've stated Aragon there is something happening, it would seem or looks to be fuel trim esq. related hence its definitely worth look at the breather system, adjusters on the inlet or even an air leak related issue.

On the breather side of things simple test nothing scientific trust me re this is while the engines ticking over open the oil filler cap here a pronounced or change in its behaviour or you feel the cap is difficult to remove(pressure feels like it's sucking the cap back down and while you're there check the underside of the cap for residue as well)it'll be reasonable to assume that you have a compromised breather system on your hands if the car had a dip stick again pull the dip stick out and you'll hear the revs change flutter and in some cases almost cut out or if it's really bad stall.

But as said its so difficult to know the only way forward is to get it checked out

[E92JMT]

UPDATE:

Hi guys!

So I took the car for a good run this morning for about 40 miles, had it retested today and it's PASSED on all emissions, problem solved!