Oil stains on concrete

[LPfishnTIM]

Originally Posted by Salty

Quint, you're wastin' your time using muratic acid and the only way you're gonna remove it with a pressure washer is to remove concrete. Since the stain is so old, this may not work, but, I've seen it work many times. Buy a gallon of mineral spirits (paint thinner). Soak the stain good and let it sit. It's best if the sun can hit it. Do it over and over and, even though the stain is old, you will start to see a difference. When it dries up...wet it again.
If you put a finish over that oil stain...I promise you it will not stay. Paint will peel and stain will not penetrate.

Good luck.

this is true, motor oil won't break down with a water base, or acid, a solvent will have to be used to break it down.