L322 4.4 M62 smoke problem

Hello everyone.
L322 2005 4.4 M62tub44 with 255000km.
After some lean codes L0171 and L0174 I replaced all gaskets and hoses on the intake along with the PCV separator (Febi Bilstein) valley pan gaskets multiple o-rings coolant hoses etc (Only two things that I see a problem during repair were the small hose that goes from the PCV to sump has been completely collapsed and my oil cap does not seal -repaired). Lean codes appear only after a long drive on the highway usually on cruise control 130km/h. Short trips are fine so far. I have an LPG on it and the conditions are the same no matter I run petrol or LPG.
Problem is that now together with lean codes I have a huge white smoke from the exhaust more on bank one than two. I looked at the top hose that connects to the camshaft cover which goes to the oil separator and separator itself and the internals of the hoses are covered with some white oily mug. I panicked and open both valve covers and all internals are clean without that mug. I clean that **** clean the oily intake and also make an engine flush and change the oil again. After 50km or so the smoke along with the white stuff inside top hoses are back. I also smoked the intake with a smoke machine and there is no leak. Spark plugs and all coils have been changed also. Coolant on top-level, filters changed (fuel filter Mann).

I did not touch MAF and O2 sensors yet but I have a lot of data from them so please anyone can tell me if they are bad or not? (attached. sorry for the local language in the scanning tool)

Can anyone identify what that white stuff is inside my hoses and where it comes from (pic. attached)?

Any advice is appreciated as I am on the edge with my mental health and also with my bank account.

Thank you all Peter.

The white stuff looks like the result of water mixing with oil. Is the coolant level dropping?
A leaking vapouriser is a possibility.

Coolant not dropping or maybe dropping so little and slow that it is not obvious. Where can I find a leaking vapouriser? I checked all fluid levels and oil seems to be too high and I know it has been right at the max a few days ago.

PetrVIVIVI said:

Coolant not dropping or maybe dropping so little and slow that it is not obvious. Where can I find a leaking vapouriser? I checked all fluid levels and oil seems to be too high and I know it has been right at the max a few days ago.

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If the oil is too high, then either water or possibly petrol is getting into the sump somehow. Does the oil smell of petrol?
I don't know that engine so can say no more.
Others that know your engine will be along eventually.

PetrVIVIVI said:

Where can I find a leaking vapouriser?

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Part of your LPG system - probably first component on the LPG pipe from the LPG tank, and probably in the engine bay, as they need to be water heated ....

If the smoke has arisen following repairs, it's likely caused by something you have disturbed ....

PetrVIVIVI said:

oil seems to be too high

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might be worth draining some out and letting it settle to see if any water appears... if it's clean, just put it back, if it isn't, well ...

+1 on Datateks comments re "does the oil smell of petrol?"

I turned off the LPG immediately once I spotted the smoke and drive only on petrol since then. I drain a small amount of oil. Oil looks without contaminant and smells only like burned oil. I start a car briefly today after sitting in the garage overnight. Some white smoke after 5 or 10 sec. appears only on the right exhaust pipe and then another one and within a minute or so it has been gone but I am not driving it yet.

I will clean the pipes again, shut the LPG off and close the valve on the tank to rule out the LPG messing with the system. Then I will give it a few long drives to see if that white stuff appears again.

Meanwhile, I need to find the cause for my lean condition codes. MAF or pre-cat O2 what to do first? I assume that my homemade smoke machine works as I pump the smoke into the intake several times and no leaking is spotted.

Also, does anybody know what brand is the original PCV valve LKR000040? I was able to buy only Febi Bilstein and some say that it needs to be the original part. Unfortunately, I put my old part in the trash a few weeks ago so I can not check.

Fedi bilstein should be right as its a bmw motor.

PetrVIVIVI said:

I turned off the LPG immediately once I spotted the smoke and drive only on petrol since then. I drain a small amount of oil. Oil looks without contaminant and smells only like burned oil. I start a car briefly today after sitting in the garage overnight. Some white smoke after 5 or 10 sec. appears only on the right exhaust pipe and then another one and within a minute or so it has been gone but I am not driving it yet.

I will clean the pipes again, shut the LPG off and close the valve on the tank to rule out the LPG messing with the system. Then I will give it a few long drives to see if that white stuff appears again.

Meanwhile, I need to find the cause for my lean condition codes. MAF or pre-cat O2 what to do first? I assume that my homemade smoke machine works as I pump the smoke into the intake several times and no leaking is spotted.

Also, does anybody know what brand is the original PCV valve LKR000040? I was able to buy only Febi Bilstein and some say that it needs to be the original part. Unfortunately, I put my old part in the trash a few weeks ago so I can not check.

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Turning off the LPG does not eliminate a possible vaporiser leak

Ok, so I have some news. I ordered a test kit for exhaust vapors in the coolant. The test did not show any (no color change) after 30 minutes. Also, I lose only a very small amount of coolant so I think it drips from some hose after all.

The first thing I do every time I have any problems with the engine is to turn LPG off just to be safe on that side. I turn it off when my check engine light came on after a long trip (high fuel trims).

From that time the car produces a massive white smoke but I finally try to turn the LPG on and no smoke at all instantly. LPG is out of my hands so I need to take it to a specialist. I am really confused now as I thought that a turned-off LPG system can not influence the engine but It looks like it can.

I have only one month till I have to do my MOT and I am not sure if I will pass with such a smoke machine.

PetrVIVIVI said:

Ok, so I have some news. I ordered a test kit for exhaust vapors in the coolant. The test did not show any (no color change) after 30 minutes. Also, I lose only a very small amount of coolant so I think it drips from some hose after all.

The first thing I do every time I have any problems with the engine is to turn LPG off just to be safe on that side. I turn it off when my check engine light came on after a long trip (high fuel trims).

From that time the car produces a massive white smoke but I finally try to turn the LPG on and no smoke at all instantly. LPG is out of my hands so I need to take it to a specialist. I am really confused now as I thought that a turned-off LPG system can not influence the engine but It looks like it can.

I have only one month till I have to do my MOT and I am not sure if I will pass with such a smoke machine.

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LPG vaporiser leaking would be my bet, it could account for coolant loss and white smoke. Turning the LPG off removes pressure from the vaporiser I think so would allow coolant in.

I send my petrol injectors for testing and cleaning. All good nothing out of specs.
After that, I took a chance and go for an MOT as no smoke reappeared since I am regularly using petrol and LPG. On emission testing, the left-hand bank is a little over the limit on petrol only. Right side ok. LPG is ok both sides.
Long-term fuel trims on bank 1 are going more than 15% on LPG and once I switch to petrol it goes down to 9%. Bank 2 is from 3 to 7%. If I am going long trip on LPG it will trigger a check engine light P0171 and P0174. The only thing that is old is the O2 sensors.

PS: I passed the MOT