I heard some loud knocking in the engine, especially when I would press on gas.

What is your question?

no engine oil light came on but it was close to the time I usually change it. When I drained the oil, I got less than a quart out. I continued to change the oil and took it for a drive around the block. The noise when away for a day and then quietly returned. I have about 180,000 miles and I'm wondering if this is a big ticket repair.