Help needed with E36 318is lambda live reading

Hi There
Question that someone can hopefully help with.
My 318is '98 failed NCT last week for high CO at high idle

Results were 0.53% (I think - will update later - I don't have sheet in front of me now) at 2850 rpm
CO and low idle and lambda were all in spec. HC's for both were also in spec.


So I'm suspecting air leak somehwere, or lambda faulty or cat gone. Started by pulling codes - got the following

RESULT: 4 errors in error memory !-------------------------------------------------------------
10 Lambdasonde vor KAT OBDII Fehler !!
Error frequency : 255 Logistic counter: 40
Motordrehzahl 2080.00 1/min Motortemperatur 94.50 Grad C Sondenspannung vor KAT 0.32 V aufgetreten vor (rel. BZ) 146.00 h
Signal fehlerhaft Abgasrelevanter Fehler (nach Entprellung MIL Ein) Fehler momentan nicht vorhanden sporadischer Fehler
Errorcode: 0A 94 D4 10 00 41 FF 28 34 BE 79 72 07 34 C1 75 74 07 43 BF 68 76 07 1D BE 77 25 0D-------------------------------------------------------------
62 Aussetzererkennung Summenfehler OBDII Fehler !!
Error frequency : 35 Logistic counter: 28
Motordrehzahl 1560.00 1/min Lastsignal 1.25 ms Motortemperatur 66.75 Grad C aufgetreten vor (rel. BZ) 103.80 h
Maximalwert ueberschritten Abgasrelevanter Fehler (nach Entprellung MIL Ein) Fehler momentan nicht vorhanden sporadischer Fehler
Errorcode: 3E 91 91 82 00 83 23 1C 27 19 99 18 09 3D 6D B2 5D 09 58 68 5F 63 09 17 2F 5D DA 0C-------------------------------------------------------------
52 Aussetzererkennung Zylinder 3 OBDII-Fehler !!
Error frequency : 21 Logistic counter: 21
Motordrehzahl 1560.00 1/min Lastsignal 1.25 ms Motortemperatur 66.75 Grad C aufgetreten vor (rel. BZ) 103.80 h
Maximalwert ueberschritten Abgasrelevanter Fehler (nach Entprellung MIL Ein) Fehler momentan nicht vorhanden sporadischer Fehler
Errorcode: 34 91 91 82 00 83 15 15 27 19 99 18 09 3D 6D B2 5D 09 2E 47 BD CD 09 14 1A BF B1 0C-------------------------------------------------------------

53 Aussetzererkennung Zylinder 4 OBDII-Fehler !!
Error frequency : 10 Logistic counter: 28
Motordrehzahl 1160.00 1/min Lastsignal 1.75 ms Motortemperatur 30.75 Grad C aufgetreten vor (rel. BZ) 56.90 h
Maximalwert ueberschritten Abgasrelevanter Fehler (nach Entprellung MIL Ein) Fehler momentan nicht vorhanden sporadischer Fehler
Errorcode: 35 91 91 82 00 83 0A 1C 1D 23 69 ED 0A 30 69 61 F9 0A 23 1E 5D 5F 0B 17 2F 5D DA 0C ==================================================

Lambda being thown up here but is it going out of range due to an air leak or is it actually faulty.

I had a look at the lambda voltage then - see you tube video below. Could anyone familiar with looking at this comment - it seems to be reacting a bit slow to me (but I haven't looked at live data like this before - ideally I know an oscilloscope would be better) and sometimes seems to stop and a midpoint voltage rather than swing from high to low.

https://www.youtube.com/watch?v=fGPEOgql3r8



I do also feel a slight surging when driving and can see the mpg guage move in time with this surging - posted about this last year here http://www.bmw-driver.net/forum/showthread.php?t=80617 (after which it did pass NCT last year following cam sensor replacement)

Check and clean the pcv valve, the breather pipe that goes to it from the rocker cover can perish and on high revs can collapse and block itself.

Thanks. Put a new valve on it 12 months ago and new pipe but I'll check it again.

I've never used the software you have to look at the live data from a lambda
before, but, from watching the youtube video I don't think the refresh rate is
helping you get a clear picture of the lambda sensors switching rate, if the little black dot
at the side of the screen is indicating when each line of data is being updated.

Yeah I think you're right there. Best to get an oscilloscope really. Or just take a chance on the 85 quid for a sensor.

Your first error code certainly seems to be pointing towards a duff sensor......

"10 Lambda probe in front of KAT OBDII fault !!
Error frequency: 255 Logistic counter : 40
Engine speed 2080.00 1 / min Engine temperature 94.50 ° C voltage
probe before 12:32 CAT V occurred before ( rel . BZ ) 146.00 h
Signal faulty exhaust Relevant error ( after debouncing MIL A ) error is
not currently available sporadic errors"

The number of times the fault has occured is listed as 255 which usually
means the fault is pretty much constant as this is usually the figure
that error memories stop counting at. However the following codes may
(or may not) offer an explanation for why the lambda may be reading
off.

Your second, third and forth codes seems to indicate a misfire on cylinder 3 and 4............

"62 misfire detection error sum OBDII fault !!
Error frequency: 35 Logistic counter : 28
Engine speed 1560.00 1 / min load signal 25.1 ms motor temperature
66.75 degrees C occurred before ( rel . BZ ) 103.80 h
Maximum value exceeded exhaust Relevant error ( after debouncing
MIL A ) error is not currently available sporadic errors

52 misfire detection cylinder 3 OBDII error !!
Error frequency: 21 Logistic counter : 21
Engine speed 1560.00 1 / min load signal 25.1 ms motor temperature
66.75 degrees C occurred before ( rel . BZ ) 103.80 h
Maximum value exceeded exhaust Relevant error ( after debouncing
MIL A ) error is not currently available sporadic errors

53 cylinder 4 misfire detection OBDII error !!
Error frequency: 10 Logistic counter : 28
Engine speed 1160.00 1 / min load signal 1.75 ms motor temperature
30.75 degrees C occurred before ( rel . BZ ) 56.90 h
Maximum value exceeded exhaust Relevant error ( after debouncing
MIL A ) error is not currently available sporadic errors"

These can and will throw emmissions off, depending how often it's happening. However the time codes would seem to indicate that
these faults may have happened quite some time ago.

Your best bet would be to delete all of the above codes and run the
engine to see which ones return. Hopefully then you'll start to get a
clearer picture of where the fault may lie.

Ok, thanks for that. I last had these codes last June and deleted them then. I assumed the misfire codes were related to intermittent rough running on startup some mornings. Like it was running on 3 cyls but it usually cleared after about 10 secs.

OK Only getting around to doing something with this now - NCT retest is next Sunday. I had cleared the codes the last time so read them again tonight. This time I only had errors for the Lambda - so I just ordered that from Micks Garage.

Started to take off the old Lambda sensor and the fecking thing started to bind on the threads:crying:

Got it out eventually though but it took a few of the outside threads with it from the boss. Maybe it's the first day sensor and this is my problem (car has 172K up on it).
Luckily I have a 18X1.5 tap so was able to clean it up. Hopefully this new sensor will sort my issue. Can't see anyhting else obvious when poking around the engine bay - spraying butane gas all around when the car is running makes no difference to revs so I'm hoping there are no vacuum leaks.

My own fault for leaving this to the last minute really but in trying to plan ahead for future tests can anyone recommend a cheap but good (:hehe!:) CO meter for testing this stuff at home?

Just to update on this
Fitted the new Lambda. The previous slight surging that I had been experiencing went after this.
At the same time I changed the o-ring on the DISA valve becasue the old one had slight damage - although I don't think it was leaking.

It passed teh NCT retest today - so happy with that.:smiling:

Once I get a chance I'll plug in the diagnostics again to see how fast the new lambda swings - to answer my own question.