Polymerisation lube oil

[Bart F-350]

I wonder, does anyone here have experience with polimerisation of the engine's lube oil?

It happened to my VW 1,9D engine, The lube oil became very thick, and I'm sure it is not the "mayonaise" like when there is a lot of condensation in the oil, or like you lose cooling fluid, when that mixes with the engine oil you get that caramel or mayonaise colored oil mix, it's NOT like that.
It is diesel engine oil, so black as soot, but then with the consistency from hair gel, like in the '80's!

What I did when I saw that; a oil change, with the cheapest oil possible, and a flush treatment with it.
Then as far as I could seen the engine was clean, and a new filter and new regular oil.
I did not look after that, assuming this happened just unforeseen isolated case.
Then a little while ago, I needed to be in that engine, under the valvecover, and again I noticed the thick layer of black goop.
and since the compression of that engine is 24 Bar, where VW says that anything under 26 Bar is worn out according to them I decided to overhaul that engine.


The thing I wonder though, is: has any of you experienced this? and / or does anyone here has a Idea why this happens?
Love to hear from you.

 

[Mt_Man]

Interesting, are you running diesel or alternative?

 

[Bart F-350]

Mostly regular diesel, but a few years ago I tried a couple of fill ups with WMO mixed with gasoline to get to the desired viscosity.

But I can't remember if the oil was thick before or after I used the WMO?

 

[Mt_Man]

Copy some report problems with running wvo and not getting burn combustion and leaking into the oil which could cause problems with polymerization. Also an injection rebuild shop local said they see lots of tractors injection systems gummed up from the bio mixed with diesel from the pump and sitting all winter. Brown sludge comes out after sitting long time.
Not quite what you have but interesting.
I haven't noticed any skins of thickening of my oil with wmo blends. Supposedly oil with thicken with use? I would think it would break down but depending on the situation could get thicker, possibly.

 

[sieg01]

Yes, this is a subject.
But I have heard about it in conjunction with WVO - not WMO.

Polymerisation can happen after WVO is mixed with the engine oil and when there is dirt in the engine oil.

To prevent this, it is recommended to double the oil change intervall. Means replacing the oil and filter at 50% of normal.

There are plenty of stories available on the German speaking forums.
No idea if they are just horror stories to scare folks. Just like with the negative talk about bypass filter systems....

Recently I read that Germans are not keen in WVO upgrades with large engines because large engine would be prone to polymerisation.

 

[Jesus Freak]

Yes, this is a subject.
But I have heard about it in conjunction with WVO - not WMO.

Polymerisation can happen after WVO is mixed with the engine oil and when there is dirt in the engine oil.

To prevent this, it is recommended to double the oil change intervall. Means replacing the oil and filter at 50% of normal.

There are plenty of stories available on the German speaking forums.
No idea if they are just horror stories to scare folks. Just like with the negative talk about bypass filter systems....

Recently I read that Germans are not keen in WVO upgrades with large engines because large engine would be prone to polymerisation.

Those na-zi-nay-sayers!

I've never heard of that, but it makes sense. WVO sure seems like more headache than it's worth.

 

[Bart F-350]

Also an injection rebuild shop local said they see lots of tractors injection systems gummed up from the bio mixed with diesel from the pump and sitting all winter. Brown sludge comes out after sitting long time.
Not quite what you have but interesting.

It's not really "gummed" up, I know, last summer I really! had a lot of work with my 7.3, also because of the Bio component in our diesel these days, the fuel system of my truck was blocked due to this algea, diesel-pest, bacteria, whatever you like to call it. nasty!!!

 

[sieg01]

It's not really "gummed" up, I know, last summer I really! had a lot of work with my 7.3, also because of the Bio component in our diesel these days, the fuel system of my truck was blocked due to this algea, diesel-pest, bacteria, whatever you like to call it. nasty!!!

Yes, you have to have an eye on the algae.

And it gets worse:
- the larger the tank is
- the less you're driving
- the longer the diesel sits in the tank

Just a tiny drop of water can cause the algae to appear.

The only solution to prevent getting it, is next to the doing opposite of upper listing - using chemicals.

 

[ut99dot1]

Check out google images and youtube for "engine oil sludge";

Oil sludge - Wikipedia

en.wikipedia.org

more frequent oil changes seem to be the remedy.

Assuming you have the 1.9D (the IDI), e.g. AEF or AAZ, 24bar is out of spec, yes, BUT it will run fine.

I have a 1.6D, runs and starts with 2 cylinders at 23-24 bar. (others are 25/26)
From stories on the internet, I get that if it gets too low it will be hard to start in the winter, then summer, then not at all, lol

 

[Bart F-350]

Oil sludge;My oil was changed every 7500Km, no liquid leaks, CVS works, Only reason I see might still be the piston rings blowby? due to worn engine.

I never had to use the cold start advance lever before, then at a certain day I couldn't start my engine in a regular way anymore, and pulled that lever.
then my engine started as it did before, that went like that for five days, and then it didn't even start anymore, not even with the cold start advance lever pulled out to it's max.
No way to get my engine started anymore, other than a pull start.
So I considered it R.I.P.