I have a 2001 Toyota Tacoma, V6, that was driven approximately 3 miles without any oil in the engine. After reaching the truck I filled the engine with oil, started it, and let it ran for a while. Since all appeared to be fine, the truck was driven for approximately 30 miles. After reaching the destination a slight noise was noticeable on the right side of the engine. After letting the truck set for two hours, it was driven, on the return trip, the same number of miles. While driving the noise got a little louder. The truck set overnight, so when it was started, the next morning, the noise developed into quite a loud tapping.
I thought the noise was coming from maybe worn lifters or camshaft lobes, but there was no miss while the engine was running. After pulling the value covers off, I measured the camshaft lobes and found that they were all within tolerance and the lifters looked fine.
Please advise on what is the possible problem or problems.