4.0 will run on one quart of oil
 

Not well, but it will.

I was outside when my daughter drove up in her 1999. I was sounding ROUGH. I popped the hood, as I began to diagnose. She said it sounded bad the night before when she drove home, and again that day.

The first thing I noticed that the oil filter had 10 Sep and 299k written on it. As there was a hurricane blowing about that time in September of THIS year, I got a chill and pulled out the dipstick.

It looked like it had been stored in the chimney for the winter, due to the creosote on it. some carb cleaner and a rag and it was clean. Came out of the tube just as clean. Not a drop of oil was on it.

I had a filter and oil, so I did a quick change. I wrote the date on the new filter and checked the odometer. 323k.

Yup, 14 months and 24k miles.

Filled it back up, and the lifters did their job. Running fine, for now.

Hurray for the mighty 4.0!

ETA: She got a stern talking to.

You might want to consider adding a quart of transmission fluid to the oil and letting it idle for half an hour before every oil change for a while, will help slowly dissolve some of that burnt on crap.

My grandad used to use kerosene! Then again, his first car was a model T!