There was a common problem with the plastic lock motors in the sliding doors causing a buzzing noise. I have a bunch of those, but I never replaced one in the lift gate so I don't know if they use the same part. The motors in the front doors are built into the latch assembly but they can make the same noise.
Start by removing the rear trim panel, then feel the latch assembly while a helper works the locks. If that's where the noise is coming from, replace the latch.
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Tuesday, August 16th, 2011 AT 1:37 AM