GMC Repair: 2008 GMC Acadia V6, 2008 gmc acadia, evap purge valve

Question
It has a loud sort of tapping noise when accelerating.  At idle there is a tapping that sounds like it is coming from what looks to be a sensor at the end of a hose that connects to air intake tube.  Two wiring harnesses connect at this point.  I don't know if the two sounds are connected they both make a tapping sound but do not sound the same.  I can not tell where noise on acceleration is coming from, but it is getting louder and louder.  It is getting so bad, my wife is embarrassed to drive car now. Also, I am having trouble with head light wiring harnesses and bulbs blowing. Any help would be gratefully appreciated.

Answer
Hi
The tapping noise MAY BE the EVAP Purge Valve. It is used by the Emissions system to purge raw fuel vapors from the charcoal canister. Changing it MAY quiet it down, but it will start again. It won't harm anything, and it should only tick while it is in purge. This is the most common noise I have heard on the hundreds of Acadias I have worked on.
GM Just recalled the Acadia for a the Head lamb bulbs and connectors to be replaced free of charge for the owners. As long as you do not have the High Intenisty Discharge (HID) system, you can have the head lamp connectors and bulbs replaced at your local GMC dealership for free.
The recall number is 11055, and came out in December. Depending on how large an area or dealership I would make an appointment, and the recall should take 1.5-2 hours to complete.
You also may want them to check the noise, in case it is not the Purge Valve.
Good Luck