modern diesel for overlanding in developing countries - post your solutions

Dan Grec

Expedition Leader
So with regards to a modern diesel, would the issue solved by simply removing the DPF and related sensors?

Unfortunately not.
The problem with "dirty diesel" is that it isn't *just* dirt (which can be filtered out), but also the insanely high sulphur content.
In the developed world Ultra Low Sulphur diesel is somewhere around 15 parts per million.
Plenty of countries in West Africa and elsewhere are over 2000 parts per million.
The sulphur can not be filtered out.

So this sulphur causes all kinds of problems with very high pressure injection pumps, with the tiny nozzles on the injectors, with the sensitive linings on the cylinder walls, by diluting the engine oil and then creating drastically more engine wear, etc. etc.

The results are not entirely known, and while you may get away with it for tens of thousands of miles, it seems almost certain that high sulphur diesel will be causing damage.

I went back and forward with the head of engine design at VM in Italy who designed the 3.0 ecoDiesel in my new Wrangler (Same engine in the RAM 1500, Grand Cherokee, etc.). He did NOT recommend running the engine on high sulphur diesel and confirmed it WILL damage the engine, even if I removed all the emissions stuff and re-flashed the ECU.

I did a big video about it all recently, now that I have a very modern diesel and intend to keep exploring the world.


-Dan
 
Were they specific on HOW running high sulfur diesel will damage the engine, even with emissions deleted?
By the above I mean clean (no water or actual dirt) high sulfur fuel.
I will make a bet that if you really pin them down, they’ll talk about “sulfuric acid buildup in the oil etc”. Which is the only negative difference between clean high and lower S fuel; high S fuel actually has BETTER injector lubricity.
The acidity reason is why “legacy” lube oils, e.g. ACEA E4/MB228.5 have increased detergents/alkaline reserve that still allow long oil change intervals with high sulfur fuel.
You hinted at that in the above post; no, I didn’t spend 21 minutes listening to a the video repeating stuff about modern diesels and diesels in general that I’ve known for decades. I apologize, just let me know if the VM guy said something like “sulfuric acid dissolves the engine from the inside out”.
Emission systems are the sole reasons I know of why mfgs adamantly forbid high SAPS legacy oil in modern clean diesels. Which neutralizes the acidity caused by high sulfur fuels.
EGR actually does significantly increase engine wear (due to soot and nitric acid) and my particular engine allows a 71% (500 hr!) extension of OCI in models sans EGR. Up to 1200h or ~42k miles in my case.
If the cooled EGR fails, the glycol getting into the oil can quickly ruin bearings.
I re-emphasize that my comment only pertains to fuel that isn’t adulterated with actual dirt or water.
Lastly: I returned home in 2017 from a 25200 mile trip to Mongolia and back. I used 300ppm S fuel all the from western Russia and back. I used 3000ppm fuel in Mongolia. I did an oil analysis on return when I changed it. Result included 44ppm Fe, <2ppm/1000 miles, which is extremely low. For reference, the “condemnation value “ (limit) for my engine (MB OM906LA) is 200ppm Fe. I was using Mobil Delvac 1 SHC 5W40, which is an E4/228.5 “legacy oil”. TBN residual alkalinity) was 11.5, down from initial 16 but even brand new “clean diesel “ oil is usually 7-10.
 
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Dan Grec

Expedition Leader
Were they specific on HOW running high sulfur diesel will damage the engine, even with emissions deleted?

Yes. He said:
"Possible failure due to High Sulfur contents can be: Cylinder liner corrosion, EGR cooler corrosion, Oil degradatio,n Exhaust pipes severe corrosion, DOC poisoned, DPF clogged."

Obviously some of them don't apply if deleted.

He also said "I do not expect major issues in case of sulfur content up to 500ppm." (which is great)

-Dan
 
Yes. He said:
"Possible failure due to High Sulfur contents can be: Cylinder liner corrosion, EGR cooler corrosion, Oil degradatio,n Exhaust pipes severe corrosion, DOC poisoned, DPF clogged."

Obviously some of them don't apply if deleted.

He also said "I do not expect major issues in case of sulfur content up to 500ppm." (which is great)

-Dan
And the remainder (in a deleted engine) don’t apply IF using a high SAPS oil: high ash, high TBN, a la ACEA E4/MB228.5 specification.
I can explain further in all the detail you require if you wish.
 
The S (sulfur) oxidizes to SO2 and SO3 in the combustion chamber. These compounds are potent electron acceptors (acid precursors). The latter in particular forms sulfuric acid when it encounters a water molecule, which is abundant in the combustion chamber since most of the the H atoms fo to H2O.
So what prevents the metal in the cylinder wall from quickly corroding?
The very very thin oil layer left on the cylinder wall after being scraped by the rings!!
That’s why my engine consumes ~1L/70 hours out of its capacious 29.6L sump.
“Modern” low SAPS, low ash, which means low additives of the organometallic type, specifically Mg/Ca detergents, which are weak bases; and Zn/P antiwear additives.
That’s because they would clog DPFs and especially the P “poisons” catalysts.
The alkalinity of a lube oil is typically quantified by “TBN” = total base number.
I’ve looked at innumerable oil specs over the years. Typical truck (for mixed diesel and gas vehicles) oils that are well known have dropped from ~10 down to around ~~7 over the last 20 years.
“Legacy” specs like MB228.5/ACEA E4 are 12-17.
So the starting TBN of the UOA of my engine was around 16. You can see after >25000 miles, including use of 300ppm Russian fuel and 3000ppm S Mongolia fuel, TBN is still 11.5, and Fe a very low 44ppm (1.76ppm/1000 miles). Iron is a significant wear parameter.IMG_7648.png
 
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sg1

Adventurer
This is very helpful. Now I understand why OEMs require a very specific oil quality for modern diesel engines which is very difficult or impossible to get in 3rd world countries. In addition at least Mercedes halfs the intervals for oil changes if a higher sulphur diesel is used. Most people with modern diesels I met on my travels used locally available oil not meeting OEM specs thus apparently adding to the problem of clogging their particulate filters. Fortunately I had an old diesel happy to burn whatever was available.
 
This is very helpful. Now I understand why OEMs require a very specific oil quality for modern diesel engines which is very difficult or impossible to get in 3rd world countries. In addition at least Mercedes halfs the intervals for oil changes if a higher sulphur diesel is used. Most people with modern diesels I met on my travels used locally available oil not meeting OEM specs thus apparently adding to the problem of clogging their particulate filters. Fortunately I had an old diesel happy to burn whatever was available.
Yes. If the external emission system (exhaust components beyond turbo) are deleted (temporarily if one wishes), AND if proper lube oil is then used, the high sulfur (rare these days: Bolivia, Peru, Venezuela, Egypt, Iraq/Iran/Syria and maybe a handful of other countries) fuel actually lubricates superfine tolerance injection parts BETTER!!
Which there’s more of on a recent “clean diesel” than a “legacy engine”. When EU and NA first went ULSD 2 decades ago, there was a pandemic of pump failures till they discovered that they needed to add stuff to lubricate fuel injection parts. Knowledgeable gearheads were putting a bit of ATF in every tank for several years.
Dirt and water are a completely different issue of course.
 

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