Biodiesel-caused injection pump failure??? - Page 3 - PeachParts Mercedes-Benz Forum

Alastair · #31 04-23-2007, 07:34 PM

Proceedure for testing BioDiesel fuel conversion.

http://www.vegetableoildiesel.co.uk/forum/viewthread.php?tid=1462

Unfortunately, just as it appears to be in the USA, there is a whole pile of cruddy fuel round here in the U.K. too...

I make Biodiesel for a living, and have done for nearly three years. I've seen quite a few Co's come and go in that time, and many 'samples' of so-called Biodiesel....Makes me mad when I see some of the crud these con-merchants sell....

My guess is to the exact problem with the fuel here in question, is that as it was made using 'Soy' oil, that it had de-graded or 'Oxidised' which is a very real problem with Soy derived BioDiesel fuel-- Particularly if it was poorly made or stored in unsuitable conditions. This issue with Soy-BioDiesel is well known. the maker should use an Anti-Oxidant such as Vit E or similar as well as an Anti-Microbial treatment.

Old300D · #32 04-24-2007, 11:50 AM

Quote:

Originally Posted by dustintegrate

Is there such a thing as BioD without methalhydroxide?

Methanol mixed with lye is just that, a mixture. contrary to popular belief, it is not "methoxide".

Old300D · #33 04-24-2007, 11:59 AM

Quote:

Originally Posted by patbob

Yes. You can use Ethylhydroxide, propylhydroxide, etc.

. The stuff made with ethyl acohol actually has a lower cloud & gel point from what I've read. I believe there's a pretty standard look-you've-made-biodiesel recipe that uses isopropyl alcohol (I live in fear my daughter's class will figure this one out and all want to make me some bioD for my car, and then expect me to put the unwashed stuff in my tank to prove to them it worked).

One can also make methylester using an acid instead. Lye is probably cheaper though.

BioD doesn't foam like dinoD when filling the tank, so overfilling is common. Plus, you've got people who have no self serve skills self serving.

This is incorrect. Ethanol is extremely difficult to use in biodiesel production. And isopropanol will not work, period. Additionally, making biodiesel using acid and a non-caustic catalyst is way beyond the scope of the homebrewer.

odie · #34 04-24-2007, 12:36 PM

Maybe I missed it but how many miles did you have on the IP? Mercs run almost forever...but not actually forever.

With the Bio eating rubber & o-rings...I thought that was from the methanol used to make the bio-D. So older diesels may slowly die on Bio until all old rubber parts are swapped for newer bio-compatible parts.

Old300D · #35 04-24-2007, 01:05 PM

Quote:

Originally Posted by odie

...
With the Bio eating rubber & o-rings...I thought that was from the methanol used to make the bio-D. So older diesels may slowly die on Bio until all old rubber parts are swapped for newer bio-compatible parts.

No, biodiesel alone will swell and eventually dissolve rubber, including nitrile synthetic rubber. New Mercedes OEM lines seem to withstand bio. Well washed biodiesel has no residual methanol.

Alastair · #36 04-24-2007, 01:48 PM

The 'Methanol content' of BioDiesel fuel is not as Free-Methanol like in a Mixture....

In the BioDiesel process, The 'Glycerol' Molecules are Substituted for much smaller Methanol molecules, thus making the fluid much less viscous....You're replacing the Glycerol with the methanol Molecule, the glycerol is removed from the process...

The resultant BioDiesel is called, 'Methyl-Ester' meaning, that the Methanol is chemically part of the fuel. Veggy-Oil is called a Triglyceride, meaning that there are Three Ester-Chains attached to a glycerol molecule The process breaks down the bonds between the glycerol and esters, and attaches a methanol molecule at the 'Broken-ends' of the three ester-chains left after the glycerol molecule has left.--Nice simplistic description......

BioDiesel is Non Toxic....

IF the 'Methanol Component 'Still had the Usual properties of Methanol, then BioDiesel would be Toxic too

patbob · #37 04-25-2007, 02:23 PM

Quote:

Originally Posted by Old300D

This is incorrect. Ethanol is extremely difficult to use in biodiesel production. And isopropanol will not work, period. Additionally, making biodiesel using acid and a non-caustic catalyst is way beyond the scope of the homebrewer.

Thanks for the correction. The theoretical and other stuff I've read claims it is possible, but I have not actually tried it for myself. And incidently, I wouldn't exactly consider the acid catalyst to be "non-caustic" itself

Old300D · #38 04-25-2007, 02:38 PM

Quote:

Originally Posted by patbob

Thanks for the correction. The theoretical and other stuff I've read claims it is possible, but I have not actually tried it for myself. And incidently, I wouldn't exactly consider the acid catalyst to be "non-caustic" itself

No, acid is quite dangerous. I was using the term "caustic" to refer to bases not acids, however, acid is "caustic" too.

spark3542 · #39 04-25-2007, 05:05 PM

Quote:

Originally Posted by edz755

I just had my 1974 240D IP rebuilt, and the rebuilder told me that my biodiesel partially caused failure of the pump. He indicated that the biodiesel I've been using is not fully 'cooked', and thus has caused considerable deposits to form inside my pump. Since this was a $600-plus rebuild, and I don't want to have to go through this again anytime soon, does anyone here know how I can determine if my fuel supplier's product has been correctly manufactured?

I buy it from our local heating oil supplier from his card lock station. He apparently buys the biodiesel from the midwest. It is soy-based oil and it is shipped to him via rail tank car.

I have a fleet of 4 diesel vehicles (3 MBs and one Ford diesel p/u), and I really want to continue to use biodiesel in them, but now I am really concerned.

I have searched this forum for specific references to pump failure from biodiesel use, but I've failed to find any solid questions or answers in that regard.

Thank you all in advance for any technical information about this problem.

I've found that there is a huge amount of misinformation about alternative fuels, and it's easy to blame a mysterious fuel when there is a failure (because no one has a firm grasp on the information). I try my best to limit the knowledge I dispense to that which I have first hand experience. If I were to troubleshoot your 240D IP failure I would start like this:

2 other MBs and a Ford run the same fuel...no issues yet?

How many miles on biodiesel on the 240D?

How many miles on diesel previous?

Who was the previous owner, and what type of fuel and what type of care did they use?

If biodiesel failure from prolonged use, others would see it and communicate to the biodiesel supplier.

I'm stepping into alternative fuels with my eyes open, and will base my decisions on firsthand knowledge and unbiased opinion. I have 8k miles on homebrew BD, and 8k more miles on WVO/RUG, so I can vouch that a Mercedes IP can withstand at least 16k of "abuse". If it needs a rebuild now, I'm still ahead money.

Old300D · #40 04-25-2007, 05:18 PM

Quote:

Originally Posted by spark3542

I've found that there is a huge amount of misinformation about alternative fuels, and it's easy to blame a mysterious fuel when there is a failure (because no one has a firm grasp on the information). I try my best to limit the knowledge I dispense to that which I have first hand experience. If I were to troubleshoot your 240D IP failure I would start like this:

2 other MBs and a Ford run the same fuel...no issues yet?

How many miles on biodiesel on the 240D?

How many miles on diesel previous?

Who was the previous owner, and what type of fuel and what type of care did they use?

If biodiesel failure from prolonged use, others would see it and communicate to the biodiesel supplier.

I'm stepping into alternative fuels with my eyes open, and will base my decisions on firsthand knowledge and unbiased opinion. I have 8k miles on homebrew BD, and 8k more miles on WVO/RUG, so I can vouch that a Mercedes IP can withstand at least 16k of "abuse". If it needs a rebuild now, I'm still ahead money.

Well said. I have over 30,000 miles now on homebrewed B100 in an engine that had 170k miles on it already.