it is hard to tell with out knowing millage but i have a 92 buick rivera same engine and trans it is upshifting it sounds like to me have it checked out by a trans shop
there is an overdrive does it do it when it is not in over drive? it might have been driven in overdrive, the d with the circle around it,this will also cause this problem i am sorry i cant be any more help a good transmisson shop is my suggestion
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The car has 97,500 miles on it ,it was given to me last November.
there is an overdrive does it do it when it is not in over drive? it might have been driven in overdrive, the d with the circle around it,this will also cause this problem i am sorry i cant be any more help a good transmisson shop is my suggestion