My girlfriend's Wrangler does it, I know its apple's and oranges here but just so you don't feel alone.

I notice it more after her AC has been running...link? I don't know but again maybe worth consideration.

 

I'll add my observations on the noise. If it's hot out (not having even driven the truck), the canister up by the clutch cylinder buzzes intermittently for a while. Also does it after being driven on moderately warm days. I searched at one point and recall that this was normal.

Good luck anyways.

 

Thanks for the tips. I think it is an electrical issue and the canister is fine. See my other post regarding possible electrical issue.

 

The buzzing sound is normal.
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