Is it common for manifold insulators to discolor? Mine looks like it has been soaked in oil after a few months. Could this indicate a deeper issue?

Discoloration of the manifold insulator itself is not a problem and won’t affect its performance. However, if it appears to be soaked in oil, it may point to an underlying issue such as a PCV (Positive Crankcase Ventilation) system fault or a related engine condition. We recommend inspecting the PCV system and associated components to rule out any oil-related issues.