Today was warmer than the past few days, and I had a slow afternoon at work, so I took some time off and headed to the hangar. I warmed the wrist pin bosses in the piston with a heat gun, then managed to push out the wrist pin with a piece of wooden dowel. Then I stuck my borescope inside and took a look.

Spalled #4 intake tappetThe #4 intake tappet looks pretty ugly. Drat. I managed to get the tip of a finger on the tappet by rotating the crank a bit, and it feels slightly rough, which confirms the borescope image.


I won't print what I said. I've been resigned to finding valve train issues since I first found metal in the oil, but I had been holding out hope that there was a cheaper explanation. At least now I know what the issue is, and what I need to do to get it sorted out.

I'll start pulling the engine on Sunday, and then figure out where I will send it. This is the second time in 3 years with cam or tappet issues, so I'll get the roller lifter mod done this time.