burning used crankcase oil??

[Cummins Cowboy]

with fuel prices so high, how much if any level of used oil can I run in my '06?? If I still had the ole first gen I think I would just burn about 5gal a tank of old oil with a fill up

 

[TURBOs4LIFE]

With my second gen I have used up to a 50/50 mix. It can be a little more smokey but not by much.

 

[fox]

Cummins says up to 5% is ok. Right now I have 2 gallons in the tank. A little more smoke but it is gone with a little heat from pulling.

 

[HBarlow]

You'll have to burn a lot of it to save enough money to pay for the new set of injectors needed.



I sure wouldn't do it with a HPCR engine.

 

[Vaughn MacKenzie]

I burned some used oil in my '03 a couple times and it caused problems. After burning about 4-6 quarts per tank a couple times it started hazing real bad from idle to WOT. The rear fender was caked black with oily soot (but oddly my MPG did not suffer, and my oil stayed honey-colored after running like that for a 1000 miles). The first time I didn't make the connection, thought it was a bad ECM which was replaced. But after the second round of burning used oil and getting the same result I figured out the oil was somehow causing it and didn't do it again.

There are already two other threads about burning used engine oil in this forum if you look back a page or two.

 

[Joseph Donnelly]

Engine oil doesn't burn worth a darn. It is too heavy to vaporize well. It is also too thick to be compatible with the tight clearances in today's engines. When you add the junk including soot and wear metals in used oil, it makes no sense. You drained out the used oil because it was too junky for the five thousandths bearing and piston clearances in the short block. Then you put it through parts with twenty-five millionths of an inch clearance. Not good. I just helped replace injectors in a 2005 Turbo Diesel engine that had seen used oil for a short while. All the injectors tips were gummed up, and if you pulled the head, the rings would be in just as bad a shape.