Used oil mixed with diesel?

[Mace Canute]

Today I had an interesting experience. I was visiting a friend who runs a garage and he had a customer in with his new-to-him Dodge crew cab one ton diesel truck. Long story short, the DPF {diesel particle filter...may also be called a CPF (Catalysed Particulate Filter) by some OEMs} had failed because of the wrong oil used in the engine (as in not a CJ-4 oil)...and up here that is a $5000 touch to replace. When the DPF fails, it causes extreme back pressure to the point that the engine will not run anymore and apparently the possibility of engine damage also exists. The filter also get VERY hot! Not a good thing (fire hazard).

I just thought I would mention it as a reminder.

 

[whiskywizard]

Not on my tractor but I do it on my boat. Twin Cummins 6 cylinder 450's. The Cummins manual says it's A-OK to add waste engine oil to the fuel, up to 5% by volume. Each engine gives me 5 gallons of waste oil and I add it straight into the two 220 gal fuel tanks. It's already well filtered; 5 minutes ago it was my primary lubricating oil. And the fuel filters will further polish it before it gets to the injectors. I have done this on all my diesel boats for years.

[edit - oops- corrected 10% down to 5%. ]

 

[ray66v]

The Cummins manual says it's A-OK to add waste engine oil to the fuel, up to 10% by volume.

Was the manual written before 2007?

Again, you have to consider how ULSD fuel changes the equation.

 

[mooseracing]

It's already well filtered; 5 minutes ago it was my primary lubricating oil.

I would bet the oil filter and fuel filter don't come close to filtering to tolerances that the IP and Injectors see.

I'm not saying don't do it, I'm still trying to find the right setup for running more WMO in my IDI diesel. Filtering just doesn't seem to cut it from what I have seen. Need to filter then centrifuge it.

 

[whiskywizard]

Was the manual written before 2007?

Again, you have to consider how ULSD fuel changes the equation.

Yes, the original manual was written in '02, but Cummins technical bulletins continue to endorse it for mechanical injection egines, even with ultra low sulpher diesel.

 

[ray66v]

Yes, the original manual was written in '02, but Cummins technical bulletins continue to endorse it for mechanical injection egines, even with ultra low sulpher diesel.

Okay, but since the diesel supplement study has shown adding used oil makes no real difference in ULSD, I have to wonder if this recommendation was made by someone at Cummins who had a personal opinion, or do they have actual research data showing otherwise?

 

[Soundguy]

Okay, but since the diesel supplement study has shown adding used oil makes no real difference in ULSD, I have to wonder if this recommendation was made by someone at Cummins who had a personal opinion, or do they have actual research data showing otherwise?

soot is pretty darn small and hard to filter out.. and abrasive too...

i guess if I was a company making engines and selling spare parts to fix them I'd tell people to run waste thru their system too. probably won't do enough damage to hurt it during waranty.. but eventually will.. and heck.. that's possibly new injector and pump sales.

sounds like a pretty good scam.. er.. uh deal to me..


soundguy

 

[IronHog]

Bulk diesel around here is bad and getting worse.........you'll get water almost every time.


Our loggers all run ATF in their machines and we treat fuel for tractors with aftermarket products.


The only way we've found to kill a Perkins engine is run it 10,000 hours or with ULSD with water (kills injector pump)

 

[evan price]

hmm WASTE product into the EXPENSIVE fuel system... not something I'd be a fan of.

works ok on big ships.. but not my diesels..

soundguy

Big ships run heavy bunker fuel in those big Diesels, heavy bunker oil is basically tar and you have to heat it with waste heat from the stack heat exchanger just to get it pumpable. The fuel bunkers have steam lines to get the stuff to liquify. As a matter or fact, they often scuttle wrecks in deep water because the cold temps will solidify the bunker oil and prevent oil leaks from the wreck when they can't pump it out.

According to emissions requirements it is no longer OK to burn WLO in the ship engines anymore. Lots of ships now use onboard filtration systems to basically re-refine the lube oil and only store the sludge for disposal.

marinediesels.co.uk The construction, operation and maintenance of large  2 and 4 stroke marine diesel engines

Click on "Horror stories" and down at the last one is a case of a Chief Engineer deciding to burn the waste lube oil and how it cost them 5 pistons and liners in the main.

 

[whiskywizard]

I'm going to have to rethink this. First, I better tell all those guys with 20,000h on their 6CTAs to stop doing this as it will limit engine life.