How to protect my grill from rust

[albow]

My second hand pellet grill is barely a year old, but some of the surfaces are showing rust on the inside, such as the lid on the burner pot and what I'll call the searing plate. What's the best way to stop this from worsening? Is it a good idea to spray these surfaces with Pam (I love it when she comes over) or just rub a light coat of oil on them after it's cleaned and cooled off? What should I do?

 

[albow]

I couldn't figure out how to delete this thread. Sorry. I reposted it to a more appropriate area.