I was cleaning my engine today, and decided to clean under the intake manifold. I took it out and it looked as if some of the plastic underneath had actually melted a bit. Has anyone else seen this? Does anyone want to check their intake to see if this is happening on them too? I'm not sure how big of a deal this is, but any help is appreciated.

The intake manifold upside-down:

You can see the melted plastic here:

A close up on the melt:

Thanks,
Colby