I see that you also have, as Beau mentioned, the air intakes blowing right towards the outboard valve covers. Maybe that has something to see with their (relatively) early corrosion. Though I must say that the manifold, turbo, aftercooler and all the rest of the engine looks immaculate - I wish mine were as clean as yours! Or did you possibly respray them, on top of the valve covers? Thanks for your kind offer. Yes, I have MANs as per my previous pic, and all the valve covers, outboard ones included, look still far from needing a repaint, in spite of the fact that they are older than yours (2003, with 1500+ hours). But never say never! It certainly doesn't hurt to include any suggestions you can send me in my MAN folder, for future reference. You can reach me via email using my username plus "@yahoo.com" as address. Thanks in advance!