Exhaust Transition on Lycoming TIO540-B - Pitting

[Skywarrior]

Hello, all -

An exhaust transition in my Bravo's engine is pitted, and must be repaired or replaced.

How does this pitting happen? Is it just part of ordinary wear & tear? Or is it due to overtemping?

My mech says he's heard that it is common at around 1000 hrs. Anybody disagree with that?

This was found during the pre-buy. I would like to prevent it in the future.

 

Chuck M.

[roundout]

They just do it. Don Maxwell told me why once, but I forgot. It's a common problem.