Two problems related to starter have been reported for the 2008 GMC Acadia. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2008 GMC Acadia based on all problems reported for the 2008 Acadia.
During times of heavy rain or when driving through a car wash, water enters vehicle interior. Water can be heard moving around in headliner of rear while vehicle being driven. With vehicle in motion water can be seen leaking out of air bag label on driver side panel between windshield and door. Inspected drain tubes from sunroof and found them to be completely clogged. Upon clearing debris clogging the tubes an exessive amount of water came shooting out and tubes drained for about an hour a non stop stream. Approximately a week or so later, started having problems starting vehicle. Tested battery and it was fine. Tested alternator and starter, both fine. Two weeks later car wouldn't start again. Upon aaa arriving to jump my vehicle we discovered the entire battery compartment behind passenger seat was completely filled and battery submerged in water. Further inspection found entire floor board saturated and headliner. Mold was also found on seats, seat belts, carpet, air vents, sun visors, and door panels.
My complaint concerns my 2008 Acadia delivered sept. 2007. Currently with less than 5,900 miles on it. It is now in the shop for failure to start for the third time. The battery is somehow being dischanged. Other than replacing the original battery, on the first occurance, the dealer service can not seem to track down the source of the problem. They say that the charging system checks out ok. It does seem to start fine for a while, several weeks, then all of a sudden it will have a dead battery over night. Nothing is ever left on. I check that each time the garage door is closed. The headlights always go out in one minute, if on. While driving I do notice the voltmeter on numerous occassions well stay at about +15 volt charging rate. I know that it should be no higher than about +13. 5 volts, and sometimes it does, but most times, not. I am concerned about a possible fire danger and being stranded somwhere. I am an aircraft a&p. My trouble shooting thoughts point to a starter shorting. I could be wrong but I would start there and prove that not to be the problem. Easiest fix first, the air force way.