I have a bone stock '08 LGT 5EAT with 55k miles on it, I've owned it since new.
I was driving on the interstate through the Adirondack mountains at about 70 MPH yesterday as I've often done before, and all of a sudden as I'm climbing a hill the car starts bucking with the revs jumping up and down as if the lock-up on the converter is kicking in and out repeatedly, or as if it's stuck hunting between gears?
It just kept doing it up the hill, really caught me by surprise, I wasn't sure it was going to make it and it seemed to be loosing power? It has never done anything remotely like this before?
I did notice that although the car was in drive at the time, it was in S# mode, could that have something to do with it?
It was fine after for the rest of the trip (took it out of #S), No CEL, but from what I understand there could still be codes?
Appreciate any help.
All the best,