Hey guys...

Before I go any further... I gave $300 for the car.. is something goes south, not taking a loss as I could scrap the car for that.

Anyways..

So I picked up a '75 240d.. unknown mileage.. 4 spd. car with quite a bit of rot but it ran. Got most of the bugs worked out and started tinkering with feeding it via waste oils.

To get started, a friend and I have been processing waste oil for fuel for several years now.. I've ran it in my 4bt Cummins repowered Tahoe and he runs it in his 7.3 IDI ford. The Cummins didn't care for it too much but the old IDI loves the stuff... actually runs better and makes more power on oil then on d2.

This isn't some flyby operation though... we batch our fuel 55 gallons at a time. This last batch was mostly aw32 hydraulic oil... ~50 gallons mixed and settled with 5 gallons of pump gas. After settling, its centrifuged for 30 hours and transferred into a holding tank which is setup with a stainless Viton sealed transfer pump, 10mic. absolute filter/water block, and a fuel nozzle.

I started out going roughly 50/50 in the main tank on the car just to see how it would go. Car ran great on it.. but after a week, I could tell the injectors were starting to coke up a bit as it was progressively taking longer to start and starting to haze.

I decided to setup a 2nd tank... found a 6.5 gallon fuel tank for a boat on CL.. $20. Plumbed it in using a greasecar 3 port solenoid valve and looped the return.

The 6.5 gallon tank now holds pump diesel with a heavy dose of dieselklean.

I cold start on the small tank and get the car up to temperature.. after a short hard run, the coking issue went away.. no more hard starting or hazing.

Once up to temp, I switched over to the main tank which is now straight W90. The car runs great on it... and literally 0 haze. The smell is definitely different.. but other then that, I'm not seeing any negative effects as of yet.

Now, I switch back to the little tank a few miles from my destination so when I shut down, its on pump diesel. Car starts like it always has and runs great so far.

From all of my time tinkering with waste oil for fuel, I've only seen problems when the engine is ran cold on the fuel. Oil needs heat to burn clean.. a cold engine, pump, injectors, combustion chamber, etc.. wont allow for a clean/complete burn which leads to coking of the injectors and/or rings. Running a 2 tank setup (which CAN be done on the cheap) is the best route to take.

Car will be paid for by tank #7

Now, I've only ran a tank and a half but so far... so good. I'll keep posting as things come up or if problems arise... I'm gonna run it 'til something major fails.

You can see part of our waste oil processor here..
Finally moved the processor... new setup.

More to come.
-Chris