Dirty Diesel (Black Diesel)

Tikvah · May 21, 2016, 03:30:40 PM

Lots of talk about using "used engine oil" to burn in diesel engines.
They use a centrifuge to separate any impurities, they separate water, and filter again. It is mixed if necessary with #2 diesel or with gasoline.

Any experience with our Detroit Diesels using this?

Seangie · May 21, 2016, 04:38:04 PM

Quote from: Tikvah on May 21, 2016, 03:30:40 PM
Lots of talk about using "used engine oil" to burn in diesel engines.
They use a centrifuge to separate any impurities, they separate water, and filter again. It is mixed if necessary with #2 diesel or with gasoline.

Any experience with our Detroit Diesels using this?

Dave - Scott did that for a while and Im sure he will post of his challenges. Biggest one was how quickly the fuel filters clogged up.

He also said it was a mess to maintain.

-Sean

Scott & Heather · May 21, 2016, 07:49:13 PM

^ yes and yes. Coach could run all day on it, but it was messy and you went through fuel filters like dirty socks. Don't recommend it.

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Tikvah · May 22, 2016, 05:18:08 AM

Quote^ yes and yes. Coach could run all day on it, but it was messy and you went through fuel filters like dirty socks. Don't recommend it.

Scott, how did you know when your filters needed changing? I assume it was no longer a 10,000 mile maintenance change.

Was your fuel being cleaned well enough before filling your tank? Did you use a second tank?

What I'm considering is a fixed location where I can return often to refuel with "free diesel".
Should I plan to replace filters with every fill up?

sledhead · May 22, 2016, 06:34:16 AM

I have done this for years but in a 900 gal tank with a pump at home . when I change the oil on my coach , trucks I drain the old oil into a CLEAN 5 gal pail then dump it right into the 900 gal tank ( all but the last bit ) the 900 gal tank has 2 filters on it 30 microns and then a 5 micron then to the coach fuel tank
yes the colour is blackish but for the amount I drain into the big tank is not that much . it is a easy way to get rid of the old oil ( about 15 gal. a year )
as for my fuel filters on the coach I change them each year or 10,000 km

dave

Scott & Heather · May 22, 2016, 07:57:16 AM

Dave I just knew the fuel filters were clogged in because the coach would get really sluggish. Even more so than it is now :-) also I ran all of the oil through it to micron cat filter. That would clog up really fast even after it was centrifuged that should say something. But honestly if you can pull it off I'd say go for it. For a while I ran like a 90% mixture. Coach ran fine on it, the only thing I noticed was a constant blue haze coming out of the tailpipe.

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Oonrahnjay · May 22, 2016, 08:08:18 AM

I'm soon to have a "modern" 4-stroke engine that's known for having "touchy" fuel injection components. Is it worth running filter-clogging used engine oil (with unknown chemical contaminants) to save a few $$$ on fuel? I guess it depends on the mileage you run every year, your access to used oil, equipment you have to filter or even centrifuge it, etc. but it just doesn't sound like something I want to do.

Not criticizing somebody "doing it their way" but just my thought.

luvrbus · May 22, 2016, 10:27:02 AM

It's not worth it I have seen it to many time in marine engines where they changed the oil and pumped the oil back into the 4000 gal + fuel tanks only to cause carbon build up and breaking the fire ring. When we went on a service call checking for used engine oil in the tank on a boat was 1st priority if found it would void the warranty then big @$# tears would flow from the owner. I strongly advise you read the DD bible for 76 years it says NO but it's your dime

Tikvah · May 22, 2016, 12:14:18 PM

QuoteIt's not worth it I have seen it to many time in marine engines where they changed the oil and pumped the oil back into the 4000 gal + fuel tanks only to cause carbon build up and breaking the fire ring. When we went on a service call checking for used engine oil in the tank on a boat was 1st priority if found it would void the warranty then big @$# tears would flow from the owner. I strongly advise you read the DD bible for 76 years it says NO but it's your dime

Could you expand a bit more? What causes the carbon build up? Why would it break the fire rings? Any problems with injectors?
What is the DD Bible?

Also, curious, would blending the used engine oil with either #1 diesel or gasoline eliminate the above problems?

eagle19952 · May 22, 2016, 03:03:17 PM

Quote from: Tikvah on May 22, 2016, 12:14:18 PM
Could you expand a bit more? What causes the carbon build up? Why would it break the fire rings? Any problems with injectors?
What is the DD Bible?

Also, curious, would blending the used engine oil with either #1 diesel or gasoline eliminate the above problems?

surely your not thinking used 2 stroke oil...

8 gallons of diesel is $16.00, the potential damage is $16,000.00.

why would you consider this ?

Oonrahnjay · May 22, 2016, 03:19:12 PM

Quote from: eagle19952 on May 22, 2016, 03:03:17 PMsurely your not thinking used 2 stroke oil...

8 gallons of diesel is $16.00, the potential damage is $16,000.00.

why would you consider this ?

Yes, any kind of used oil has dirt (non-combustion derived -- that's why they check for silica on oil analysis), soot (carbon from combustion), chemicals from combustion and other places (we always hope not trans. fluid or antifreeze coolant), water, etc. Used oil ... sorta like drinking water from the sewage pipe, right? Clifford has it right -- wanna see an engineer from a company that manufactures engines faint???

eagle19952 · May 22, 2016, 05:01:00 PM

. Used oil ... sorta like drinking water from the sewage pipe, right?

worse...antibiotics are $1.50...

Jim Eh. · May 22, 2016, 06:22:26 PM

Probably a wee bit illegal in most places.

kyle4501 · May 22, 2016, 06:26:11 PM

Quote from: eagle19952 on May 22, 2016, 03:03:17 PM
8 gallons of diesel is $16.00, the potential damage is $16,000.00.

why would you consider this ?

My thoughts EXACTLY !

Not to mention the cost of filters and clean storage - not saving much at all.

chessie4905 · May 22, 2016, 07:29:25 PM

I burn my used oil in my waste oil furnace in the shop. Less hassle than trying to save some bucks on coach by running it through the engine. Also any residue in the used oil will end up in the bottom of coach fuel tank over time, which will get stirred up and end up in the coach fuel filters. The ash content of the used oil is much greater than diesel fuel and will end up on the piston and rings. But it is your coach, go for it if you like.