Changes in Lubricating Oil with Biodiesel?

[CueBall Junior Member Find all posts View Profile Close CueBall]

Since Biodiesel does not contain sulphur and has slight solvent characteristics, I am wondering if with continued use, the lubricating oil in the sump will become less dirty and less damaging to the bearings etc.

I understand that one of the reasons oil changes have to be done so often on diesel engines is that the sulphur in the fuel builds up within the lubricating oil in the form of sulphuric acid. i.e. the lubricating oil would become more acidic over time, with the attendant damage it caused to bearings and bearing journal surfaces, as well as any other moving parts in contact with the oil.

Given the solvent characteristics of biodiesel, the fact that combustion of the fuel injected into the combustion chamber is not 100% i.e. that some fuel remains unburnt and can enter the lubricating oil, that no more sulphur is being added to the combustion chamber when using biodiesel and the small amount of blowby that is intrinsic with all piston engines, whereby some combustion chamber products including unconsumed fuel find their way into the lubricating oil:

Will the lubricating oil become less acidic with biodiesel use as there is no sulphur within the fuel to produce sulphuric acid within the lubricating oil?

Will the lubricating oil become less dirty with time as the accumulated deposits within the crankcase are dissolved away by the solvent capability of any biodiesel that accumulates within the lubricating oil and either captured within the oil filter or carried in suspension and flushed out with oil changes?

In other words, will use of biodiesel actually "clean" the crank-case and lubricating oil over time, and produce less damaging combustion by-products both within the engine and without?

I await your accumulated wisdom.

In friendship

Quentin

[reg Junior Member Find all posts View Profile Close reg]

Re: Changes in Lubricating Oil with Biodiesel?

Hi cueball,
Apparently so, i was talking to a guy who has been using homemade bio diesel for a couple of years in his engine and his mechanic was quite surprised how clean the oil was when it was due for its service it stayed a golden colour for much longer.
This guy extends his oil change intervals due to this.

[stephen Biofuels Forum Newbie Find all posts View Profile Close stephen]

Re: Changes in Lubricating Oil with Biodiesel?

I would still change your lubricating oil every 5000km simply because of the metal waste in the oil, which accumulates. I was told by someone who was in charge of a oil sampling lab, who said it was better to use lesser quality oil and change it more regularly than a better oil used for longer, he said the more you change your oil the longer your engine will last, period.

[CueBall Junior Member Find all posts View Profile Close CueBall]

Re: Changes in Lubricating Oil with Biodiesel?

Thanks Reg and Stephen for your responses.

I come from a diesel fitting background, - both maintenance and rebuilding, and fully agree that regular oil changes are the best insurance and preventative maintenance that can be performed on any internal combustion engine. I have always changed both engine oil and filters every 5000kms on my personal vehicles. So I definitely do not advocate extended oil change intervals.

When I started this thread, it was to see if anyone had or knew of any anecdotal, personal or attested evidence as to additional benefits of using biodiesel within a diesel engine over a longer term in terms of lessening lubricating oil degradation.

Sulphur in petrodiesel producing sulphuric acid is not the only contaminent that builds up over time within lubricating oil, particularly with the normal short trip driving that most people engage in i.e. where the engine is repeatedly run then allowed to cool to ambient temperatures.

Any engine that is run continuously or comparitively so can have extended oil change intervals simply because of this fact - think long range trucks or diesel-electric locomotives that do hundreds of thousands of kms between oil changes. But also remember that they also have additional oil filtration/purification equipment not found on domestic vehicles. Also remember that often in such situations, oil sampling is done at regular intervals to ascertain the condition of the lubricating oil, and the oil only changed when contaminents have reached certain levels or additives have fallen below certain levels

So, to get back to what prompted me to start this thread.
As I outlined in the starting posting of this thread, I suspect that there could be additional benefits in using biodiesel as one's fuel within one's diesel engine. However, not having access to an analytical laboratory and not having test engines run under controlled situations, I have no ability to verify such a claim.

Thus the input of others with experience is welcomed. That is why I said anecdotal, personal or attested evidence, as others may have done such research already or have built up a knowledge base from their own experience or know of someone who has.

Possibly, a Mechanical Engineering Department in a University would be the best people to do a project on this thought, but I don't have one in my pocket.

I look forward to your responses.

In friendship

Quentin

[Robert Administrator Find all posts View Profile Close Robert]

Re: Changes in Lubricating Oil with Biodiesel?

I've heard loads of stuff anecdotally and second hand, so nothing terribly scientific to mention, but here's one example:

I was told by a member of the elusive Melbourne Biodiesel Club that one of their members once turned up to one of their meetings who'd done 100,000Kms on biodiesel and still had the same, clean sump oil which he drained and showed the other members .
(Darren, if you read this please correct me if I'm embellishing the story ).

Land Rover also feature some sort of advanced fancy-pants oil filtration (I think they say it's a centrifugal filter?). My oil change/regular service intervals are set at 20,000Kms because of this. I know that this is true for the Discovery and Freelander Diesel models - not sure about the others. Of course, they recommend rough driving conditions warrant earlier intervals and drivers who care about their vehicles may also want shorter time between changes, but the regular, warranty specified time is 20,000Kms or 12 months.

I too would be interested to hear any other stories, or real scientific tests on lubricating oil's performance on biodiesel.

[CueBall Junior Member Find all posts View Profile Close CueBall]

Re: Changes in Lubricating Oil with Biodiesel?

Robert,
Just a quick note with regard Landrover Discovery TD5 diesel engine filtration systems.

A site to visit to see a picture of the centrifugal oil filter is
http://www.disco2.com/tech/td5engine/

These filter systems are called seconday or "by-pass" filters as they are not fitted between the oil pump and the bearings etc, filtering the full output of the oil pump. Instead, a small volume of full-pressure oil from the oil pump is filtered through such a unit and allowed to drain directly back into the sump. Thus a small amount of lubricating oil is being very thoroughly cleaned and returned to the sump when the engine is operational. Particles down to three microns and less are removed from the oil via such filters.

Larger units on large trucks, rail and large marine engines are serviced by cleaning the central spinner, however smaller units such as is fitted to the TD5 engine are disposable and are replaced much as typical spin-on full flow oil filters.

Hope this helps

In friendship

Quentin

[hdj80 Senior Member Find all posts View Profile Close hdj80]

Re: Changes in Lubricating Oil with Biodiesel?

Another very important point is that "Oils arn't Oils"
I am going to make this as simple as possible as I am nowhere qualified in giving advise but if you are at all concerned find out...
If you have a Japanese/Euro Diesel use only oil developed for those engines, if you have an Emerican Diesel use those oils (API).
You will find that the likes of RX Super is designed for sloppy Emerican engines and could cause issues with your expensive jap/euro diesel. The sad thing is that Australia has adopted the API (Americam Petrolium Institute) standards for oil, those standards are based on their sloppy engines and not the close tolerance engines from jap/euro. Use Caltex CXJ (J=Japan) Oil or similar. In fact there are probably only 3 or 4 oils sold in Australia that actually should be used in Jap/euro Diesel's, sad but true..When I changed from RX Super in my HDJ80 to using CXJ there was an initial big increase in oil consumption as the crap from the rings got cleaned up, at oil change the oil smelt vile but after 2 oil changes that all when away and that $10k engine runs sweet. Landies should be OK on API oil...
My 91 HDJ80's 1HD-T engine was known to have major Bigend failures at between 70,000km's onwards. This was fixed by Toyota replacing the BE bearings. NB: Toyota Japan never had this problem.
I had my bearings replaced at 75,000km and they were flaking and would have failed in approx 50,000km's. Oil was never blamed but independant sources have some convincing explainations on what did cause the failures and the bearings that have being used to replace the earlier bearings were basically designed to tolerate the API Oil...Anyway I don't want to get into this too much but as I said if you are at all concerned about which oils you should use find out...
I also believe that since dino diesel is no longer washing the bores and contaminating the engine oil and that bio is now doing that work, my engine should only be happier.
I have not carried out an oil change on my 80 whilist it has only run B100 for the whole 5,000km's, that time is coming up soon and if I see any noticable differences in th WEO I will certainly let the list know.

[morris Member Find all posts View Profile Close morris]

Re: Changes in Lubricating Oil with Biodiesel?

Quentin,
It is reported that b100 does not combust fully in the cylinder, and there is minimal drift past the rings, and over time there is a dilution of oil. This is true of BD as it is Petrodiesel. Therefore it is recccomended that standard intervals be followed to insure minimal degradation of engine parts. If it were not for this combustion factor, there is no eveidence (that I can find) to give any clear reason why intervals could not be extended. It would require some testing of the lubricating fluids to determine this. That would address the issue once & for all. Anyone up to sampling and testing their oil on a regular basis? ML

[darren leonadas Senior Member Find all posts View Profile Close darren leonadas]

Re: Changes in Lubricating Oil with Biodiesel?

So, to get back to what prompted me to start this thread.
As I outlined in the starting posting of this thread, I suspect that there could be additional benefits in using biodiesel as one's fuel within one's diesel engine. However, not having access to an analytical laboratory and not having test engines run under controlled situations, I have no ability to verify such a claim.

Thus the input of others with experience is welcomed. That is why I said anecdotal, personal or attested evidence, as others may have done such research already or have built up a knowledge base from their own experience or know of someone who has.

Possibly, a Mechanical Engineering Department in a University would be the best people to do a project on this thought, but I don't have one in my pocket.

I look forward to your responses.

In friendship

Quentin

Hi All from Smelbs,,As Robert said earlier, yes it is true that one of our melbourne members, Probably the most senior in age, and a retired and passionate diesel mechanic, showed us all at a meeting his engine oil. To correct Robert he didn't actually drain any oil out, he just pulled up the dip stick and showed us proudly the colour. And yep it still had the clarity and colour of scotch whisky or nice honey clean oil. He had not changed the engine oil in his 90's landrover for aprox 100,000 kms , "only to do a test for his own understanding", ( don't nesecarily do this at home kiddies), And he had been running B100 for longer than that, (100,000 ks) and had done many changes before to get rid of all the crap left behind from the evil Fossil diesel.
Old Franks prognosis was that biodiesel leaves behind no particulates. That ugly carcinigent macro molecular black **** that puffs from fossil diesel exhausts, and old frank suggested thats what turns fossil diesel engine oil black as., as it creeps down the bore into the engine oil.
Frank suggested from experience as a diesel mechanic, the sump oil in any fossil diesel will turn black almost imidiatly after changing as it sucks up all that gunk in the sump. Also that black soot (if you like) has an abrassive quality not good for your engine. At the end of the day old Frank was making a point that he believes B100 will extend the life of your engine. He was not making the point that you could be slack about changing your oil. Also Frank had done some sort of flush out of his sump before the test, to further prove or disprove the results of his experiment.
So I hope this clears up what i said to Robert, and others, at the BAA conference.
Cheers Darren.
Oh Yeah , and Ol' Frank said that any puffs of white smoke from putting your pedal to the metal in a biodiesel, is unburnt fuel. Just to add to what morris has suggested.