Hello all, thanks in advance for taking the time to help me out.

I have a 2009 2.3. I am fair with mechanic work, and usually do everything myself. I had a local mechanic do my oil change. Unfortunately, the truck was out of oil 300 miles later and developed a knock. I immediately threw the truck on the lift and found a shredded rod bearing. No problem, threw a new kit on. Started truck up, immediately knocking again. Same bearing chewed up.

Pulled the engine, sent the crank to machine shop. They ground the journals down and sent oversized bearings with the crank. While engine was out, I put brand new rods, pistons, and rings in, and had cylinders honed. I get engine all buttoned up and back together, no issues. About 10 minutes of running she starts knocking again.

At this point I am genuinely confused, I have done everything to spec EXCEPT verify cam cap position. I did not keep track of the cam cap order. I performed a pressure test, cylinder #2 shows 25 pounds. Put some oil on cylinder and checked again. 25 pounds again. So it’s looking like a valve problem.

I never sent the head to machine shop. No issues were noted on my inspection, nor have I had any issues beforehand.

Knock sounds similar to rod knock, but is not present at idle. Only present on first second of startup and light load. Stethoscope makes me think the issue is not in the bottom end. Also there are no flakes in the oil, which further adds to my suspicion that the bottom end is not the issue.

I am losing motivation to tear this truck down and every day get closer to just throwing a new engine in it. I would love to hear some advice and any experiences you have had with the issue. Thank you!