What do you think of these
I've had a missfire on both cylinders 3 and 4. Tracked it back to a vacuum leak issue between the intake manifold and throttle body. So I removed the manifold and installed steel inserts. When I did that the runners on 3 and 4 were covered with engine oil while 1 and 2 were dry. I thought weird. I also found a few pieces of something in the manifold. They were hard, but I couldn't tell what they were. So I ordered an endoscope/borescope.
Cylinder 3 looks caked with carbon build up while 4 looks like the piston hit the head. That would also explain why my sparkplug in cylinder 4 was touching the electrode. Time for a rebuild/replacement?