I own a 1995 LeSabre with the same engine (And maybe the same trans, but I don't know that).



The 3800 will take a lot of abuse. My Buick has been neglected all it's life, and the engine runs like new. I wouldn't be too concerned there. We had a 2000 Impala that needed plugs and wires. It stuttered and misfired, but we didn't have any real problems with speed.

My gut says that there is something wrong with the transmission. I think it's probably slipping. Since you're in the Dakotas, you probably drive on the highway a lot, so it takes longer for problems to progress.

What happens if you try to accelerate pretty quickly, while manually shifting gears? Does it respond well?