I would like to get opinions on mixing my used motor oil with diesel fuel. Will it hurt the engine (7.3 IDI)?

 

Personally, I can think of a bunch of better ways to dispose of used oil. Though I don't suppose it would hurt an IDI if you cut it thin enough.

 

I filter my veggie oil down to 5 microns, I'd do the same for used motor oil.

Though I've never done it, I'd probably stick in the 5-10% range.

Burning used motor oil in a motor vehicle probably not good for EPA standards.

-Randy

 

Used motor oil mixed in with the fuel will raise the BTU output which in turn makes the truck run better.

BUT,

The oil also contains fine metal particles.
These may be steel, chrome, brass or aluminum.
Not good things to run through your IP or injectors.

Also there may be sulphuric acid compounds in diesel oil.
Sulphur burning in the fuel which blows by the rings and water mixing in from condensation.
Another thing you don't want to run through your aluminum IP housing.

And lastly remember the old 6.9 IDI engines that had head gasket trouble usually on the back two cylinders from engine oil vapors out of the CDR valve?
The vapors seemed to wind up in the rear two cylinders for some reason and the extra BTU's created would raise the cylinder pressures which raised the head off the head gasket enough to make the head gasket fail.

So to sum up, it would run just fine, better than regular #2.
But there are some other issues to deal with that could be expensive to fix.

 

hmmmm-100% wmo--and still runs fine--oh well-have to tell the truck that---

 

I now have a 88 f-250 7.3 that has had the old oil from itself and any other vehicle Ron (the previos owner) had at the time (gas and diesel) put into the tank after it had settled for a few days and has 256,000 miles on the original injector pump. I still run all of my oil through it and have had no probs. yet.

dj

 

No kidding. You just drain it, and dump it in the tank? How much oil per tankfull? Any filtering other than lettng it settle?

 

If you're running a 6.9 IDI, your secondary filter - the one mounted on the front of the passenger side cylinder head - typically filters to around 5 microns. Here are some examples:

Baldwin BF786 2 microns @ 50%, 7 absolute
Fleetguard FF5035 8 microns
Purolater F50298 3 microns @ 88%
Racor PFF811 7 microns
Wix 33811 6 microns

 

Usually 10 Quarts split between the two tanks

no filtering other than the stock filter.

hope this helps

dj

 

i filter used oil with a old bed sheet leting the oil drain over a old heavy marine magnet. you should see the trash the magnet picks up from use oil out of a 2003 acura 3.2TL. most of the time i filter twice, just to be safe.

 

Bob,

What do you mean by "marine magnet?" What is the original intended use for it, size, shape, etc. Is it one of those magnets that you fish things up from the bottom of the lake with?

Do any of you who are running wmo have any issues with excessive smoking, hard starting or any other drivability problems? What about fuel filter life? Have you ever tested a combination of wmo and diesel fuel in a jar to see if it falls out of solution after a period of time?

Gene

 

Gene,

yes the type of magnet i use is just that, it's about 2" thick and 4" long. the "marine" magnet is the only one that i've been able find around here. the only reason that i called it a marine magnet is cause that is what was stamped on it. i picked it up at the local boat shop.
as for the excessive smoking and hard starting, i have no issues like that with my truck when running used motor oil.
and no i've not tested the combination in a jar, but now that you've said i think i will.

 

Thanks for the reply Bob. This is a very interesting subject. I have a friend that runs the County shop and payes to have waste oil removed and another that has an oil change bussiness in Texas and drives a Powerstroke. Both of them could bennifit in a big way from burning waste motor oil.

The link above for the commercial oil cleaning and fuel blending machine talks about a 7% blend ratio and one poster in this thread says he has used 100% wmo. More to learn, but very interesting.

Gene

 

I don't burn 100% but I have never had a smoking or starting issue.

dj

 

I should have made it clear that i do not run 100% wmo, I use around about 5 to 7gal. per tank and my rig is a 89 f350 7.3l 4x4 with 2 tanks, i think that they are 23 or 25gal and 17 or 19gal. not sure. This could be a factor as to why I don't have starting and smoking issues. If your going to run wmo in your rig you should filter it in some way just to be safe. I filter and use a magnet, and i change my fuel filter around 2500 to 3000 miles all the time. with the wmo mix I see little bit better mileage.