Had a family friend that bought a used cargo 1985 Dodge Mini van with a 2.2L. It was a sludge maker. I did a few things to clean it up. I put one quart of Road Diesel in and ran till real warm. Crusty crud came out. I then did two oil changes but put a pint of diesel in the oil the first one and did low load diving for 2 miles. The second dump was still very black.

He had heard that a pint of diesel mixed in the gas was the same as Seafoam. Well if some was GOOD, more was BETTER. He pumped 1 gallon of diesel in with 10 gallons of gas. He made it 5 miles, I had to tow him home. Flushed out a bunch of dirty gas out of the gas tank.

Diesel is a very light weight lubricating oil. It does NOT have much cushioning for bearing. It is also a solvent.