Looking for help with common problem with a twist...

I've learned that the diffuser (upper left of fridge) piece is notorious for going bad and creating a clicking sound every 5 seconds (sound of small plastic door opening and closing constantly). I've read examples of where this piece was replaced and problem solved.

However, in my instance I'm also getting a small amount of ice build up around the diffuser casing which is tacking on to the problem and excelerating the breakdown of the diffuser (I think).

The current freezer temp is set to 2 degrees and the fridge is set to 37.

Any help would be great.