1997 Voyager thumping noise EVAP?

I have a 1997 Voyager that I am having a thumping noise that is coming from a black module that is mounted in the engine compartment over the passenger side fenderwell. It has 2 vacuum lines and an electrical connection coming off of it, one of the vacuum lines has a tag on it that says EVAP. The enging seems to be running fine, although every now and then it seems like it might idle a bit rough, and there are no CEL on or codes in the computer. My question is, what is this module called, and is it just bad, or something else causing it to do this. Is it anything I should even be concerned about since the vehicle is running fine and there are no codes? Thanks for help.

If this is what is making the noise: it is the purge solenoid. The PCM turns it off and on; sometimes pulsing it pretty fast.

Yes, that is the part. Is it normal for it to be making a loud enough noise to be heard inside the van? I never noticed anything like that on my wifes 99 grand voyager, also with the 3.3L

I guess as the rubber it is mounted in gets harder with age it would not insulate as well. Make sure nothing else is contacting it.