2.4 MK7 - White smoke when cold

[drivetheglobe]

Hi,

I observed this winter that until my 2.4 engine (2007 build camper) is warm, it generates quite a hell of white smoke. I think it sounds also little rattling till then.
When warm, all is fine, no smoke, engine quiet, has power.
It starts fine since I have new starter and battery.

What could cause that?

[knobby1]

Hi,

I observed this winter that until my 2.4 engine (2007 build camper) is warm, it generates quite a hell of white smoke. I think it sounds also little rattling till then.
When warm, all is fine, no smoke, engine quiet, has power.
It starts fine since I have new starter and battery.

What could cause that?

What fault codes are you getting..??

White smoke or steam..??

Lord Knobrot

[drivetheglobe]

Hi,

Sorry for late reply- was now able to check the codes and spend a little time with it:
It has only 2 codes in PCM, U0140 and P068A.
U0140 I dont know where it comes from, I dont have any known issues with things connected to the BCM
P068A - This is beacause I have removed the 2nd battery, Tried to put the settings correct to tell it that I don't have a 2 Batt system any more, but still this remains. ( I disconnected the releais and replaced it with a copper bar...)
See full Forscan extract below ( German ..:-/).

Regarding steam or smoke - cannot really say. I tried now ( was about 0C outside) to start and see if it comes - but could not test to much - its Sunday .
It seems that the smoke is not there at the beginning, comes after a while - to finally disappear when everything is warm.
Could not recognize any specific smell different to exhaust - at least now when it was idling or standing still ( how to smell when I am diving ? )-

Had also a look in the oil inlet: looks clean. When open and motor idles, air is pressed out, but no smoke visible ( motor was not yet warm).

Looked at the cooling fluid: its somewhere in the middle between min/max and was last filled during Summer holiday in Greece when it was warm e.g. some 3000km back ( had the charge air hose exchanged as it was broken, and they filled up also the water...)

many thanks!
drivetheglobe


Here the Forscan summary:

===PCM DTC U0140:00-28===
Code: U0140 - Kommunikation mit dem Karosserieelektrik-Steuermodul ging verloren.

Status (-28):
- Vorher gesetzter DTC - Nicht vorhanden zum Zeitpunkt der Anfrage
- Fehlfunktions Indikator Lampe ist AUS für diesen DTC

Modul: Motorregelungs-Modul

Standbild #1:
-EVENT_TIME: 692410 s - Event time
-TOTAL_DISTANCE: 143587 km - Abstand insgesamt
-MODULE_VOLTAGE: 12.0 V - Modul-Spannung
===END PCM DTC U0140:00-28===

===PCM DTC P068A:00-28===
Code: P068A - Motorsteuergerät/Antriebsstrang-Steuergerät - Leistungsrelais hat zu frühzeitig ausgeschaltet.

Status (-28):
- Vorher gesetzter DTC - Nicht vorhanden zum Zeitpunkt der Anfrage
- Fehlfunktions Indikator Lampe ist AUS für diesen DTC

Modul: Motorregelungs-Modul

Diagnose Fehler Code Details

Dieser Fehlercode kann verursacht werden durch :

Zeitweilig auftretender Fehler.

Relais beschädigt oder defekt

Stecker beschädigt oder verunreinigt.

Verkabelung und entsprechende Sicherung prüfen.

Möglicherweise besteht ein Wackelkontakt in der Verkabelung. Verkabelung prnfen.

Standbild #1:
-EVENT_TIME: 691095 s - Event time
-TOTAL_DISTANCE: 143020 km - Abstand insgesamt
===END PCM DTC P068A:00-28===

===OBDII DTC Nichts===
Erfolgreiches DTC auslesen, keine Fehlermeldungen gefunden

Modul: On Board Diagnose II

===END OBDII DTC Nichts===

===ABS DTC Nichts===
Erfolgreiches DTC auslesen, keine Fehlermeldungen gefunden

Modul: Antiblockier-Bremssystem

===END ABS DTC Nichts===

===BCMii DTC Nichts===
Erfolgreiches DTC auslesen, keine Fehlermeldungen gefunden

Modul: Karosseriesteuergerät

===END BCMii DTC Nichts===

===RCM DTC Nichts===
Erfolgreiches DTC auslesen, keine Fehlermeldungen gefunden

Modul: Modul - Sicherheits-Rückhalte-System

===END RCM DTC Nichts===

===IPC DTC Nichts===
Erfolgreiches DTC auslesen, keine Fehlermeldungen gefunden

Modul: Kombiinstrument

===END IPC DTC Nichts===

[drivetheglobe]

Hi,

Was trying this morning again. Maybe has some "blue" in it, especially directly at the exhaust - in the air it looks more white. Also smells little like oil (?)
Starting was quite ok - was now standing still quite a time - but I feel its needed too many turns. Batt was completely full loaded, so turned really fast.

Have about 140tkm on it . Something "common " at that "age"? ( Age is: buit 2007, registration date 2009)

Regarding the error codes:
P068A, U0140 - to be honest cannot be 100% sure if they were not present also before my remove of 2nd batt.
If I read the description of P068A - it refers to another relais, not to the one connecting the 2 batts. Right?

[tranmx2]

Forscan has:
Present at time of request - Zum Zeitpunkt der Anfrage anwesend.
Not present at time of request - Zum Zeitpunkt der Anfrage nicht anwesend.
You can delete/ reset all DTCs - start Forscan again - to see if DTCs come back --- are present at time of request - Zum Zeitpunkt der Anfrage anwesend.

Your list from the diagnostics show - Nicht - for all DTCs.

Is the vehicle left in a cold/damp place?
White smoke - unburnt diesel or water vapour. Water vapour possibly due to the vehicle not being started for a long time - condensation in the exhaust. Coolant leak can be greyish may have smell from antifreeze. Coolant leak after the engine has cooled. Exhaust/engine needs to be cold/hot enough for it to show.
Unburnt diesel/oil may show when the exhaust system is hot enough.
It can take 5 to 7 minutes of driving for the engine eng/coolant to reach operating temp'. Ambient temp', wind speed, humidity etc have an affect as they do at cold/hot engine start.
It is neccessary to check the state of the exhaust at cold at operating temp at time intervals of about 20 mins up to about 2 hours in use.

how to smell when I am diving ? Stop - go and look/smell the exhaust - switch off eng' - the end of the exhaust is usually not hot enough to burn you - put your finger in the end rub the inside of the exhaust - look at your finger for oily soot or just soot or no soot. If a bit hot use a stick and a rag.

U0140 communication DTC. https://www.obd-codes.com/u0140.
P068A https://www.obd-codes.com/p068a
When reading about codes it is neccessary that you know exactly what is on your vehicle and to what the code refers to. What the manufacturer put on the vehicle - what was done re' the camper van conversion.

had the charge air hose exchanged as it was broken - could result in exhaust anomolies.

(2007 build camper 143020 km - 88868.5079 miles )I think it sounds also little rattling till then - wear on the timing chain/ guides etc - slow oil pressure to the timing chain tensioner. May have hydraulic tappets.
Has it had regular oil changes with flushing oil?
Infrequent use. The oil shall drain away from moving parts when the eng' is not in use = wear each time it is started.

[drivetheglobe]

Thanks - lot of input! Will need to keep observing exhaust, water, oil, ..
Could this be a malfunction EGR as well?

Was starting now again, but now it had some 8-14C when starting - no smoke!
And has really power - driving in the Alps now, up to 1500m on steep winding roads, not fully loaded for a camper (:roll:) but 4 people with ski in it at least..

Will see if it falls again below 0C or so in the next week(s) or so to check if it smokes again and if this is really so ambient temperature dependent - or it was just a coincidence.

But if Spring is really coming maybe next test is only next winter...
Anyhow, I will try to replace the relais for the PCM to see if P068A will go away.

[drivetheglobe]

Hi,
Was now driving around 900km in the Alps, and checked some of above:
- we had also some cold mornings and at ca 1C it is again smoking white: starting with I would say more turns as usual but without problems and it I started moving it or give more gas after some minutes there is lots of white smoke ( or steam). I think again definitely more one is seeing from cars with cold exhaust.
- coolant: I lost ca 1/3 between min/max on that 900km.
- I checked for leaks. Found only 2 places where there was something red, but it was dry ( in today morning after we arrived yesterday afternoon, its warm outside 20C)

20240331_120518_1080.jpg

Seems to be the waterpunp !?

20240331_120845_1080.jpg

Last one has new hose climp - so think it was repaired before I bought it.
- Motoroil looks nice, no foam, seems same heighth as before ( Seems its using some oil, as I refilled soe 3/4l after summer but seemingly not so much)
- DTCs I have deleted all now, and started shortly and did not come back, I ll observe.
- Exhaust: tried to see if there is oil, but think I dont have enough expierience -or there is nothing special - for me its just soot.

Had a look on the EGR cooler - Uff - found it after a while... its located quite unluckily behind the motor - can it be exchanged without removing the whole motor
( was thinking to take it out to see if its ok)

[knobby1]

If you're loosing coolant with no obvious leaks, it's probably the EGR cooler leaking internally....coolant is then going out the exhaust as steam. You can by-pass the EGR cooler to eliminate it from the system....and replace it later.

Lord Knobrot

[drivetheglobe]

Thanks - you mean let the water not go through it? No temp issues with that ?

[knobby1]

Thanks - you mean let the water not go through it? No temp issues with that ?

That's correct....just connect the two coolant hoses with a short 15mm piece of pipe. There's millions of vehicles out there without an EGR cooler...doesn't hurt them. If it turns out your EGR coolers is the culprit, just replace it when you get a chance.

I ran my 2008 2.4 140 without an EGR cooler connected to the cooling system for nearly 18 months...If I'm honest, I couldn't tell the difference. It's all back to standard now though.

Lord Knobrot