So, way back in my Navy days, we had a young sailor who was electronics/fire control specialized. He barely knew how to use a screw driver. He asked us about his car, it was old and was making some noise. I asked him if he was getting oil changes in it, etc. He just looked at me, so, told me everything I needed to know. He was driving it back home to Ohio for Christmas (we were in Connecticut at the Sub Base.) I told him to ensure the fluids were at the full mark. So, I heard much later, that he only had the oil level at about 3/4 or so. So, since he was leaving in the morning, he filled it to the full mark..........with water. Now, small engine, can't remember exactly what it was, but probably only took a quarter of a quart to get it to full mark.
Car was still running. So, there we go.
Forgot to add, he sold the vehicle to a young sonar tech on the ship. My guess is, that friendship had an expiration date on it.....
Not sure what happened to vehicle, I transferred to shore duty shortly thereafter.
So, if you're in Ohio, and you're buying a vehicle from a guy named "Schmiddy".............don't.