(I have a 1998 STS with 105,000 miles) today I was picking up my daughter from Daycare and when I pulled into my parking spot my RPM's reved up to 2,000. I then just shut my car off and went inside to get my daughter. When I left daycare my car seem to shift into gear pretty hard, but once it was in drive it shifted smoothly all the way home up to 60mph. The weird thing was.... when I was driving on the highway my car would maintain the speed I was at. When I let off the gas pedal the car maintained that speed at which I was driving! It was like I had the cruise control on! But I didn't. When I had to go 25mph I would have to ride the brakes because my rpms were at 2200. When I finally pulled into my garage and I put my car into park my RPM's reved up to 3200. I then shut the car off and had it towed to a dealership where they will look at it tomorrow sometime. I probably shouldn't have driven it home but I didn't have too many options. IF anyone has ever had this kind of problem or know what it could be please feel free to give me some insight. Hopefully I won't have to find a new car! Do you think it could be a stuck cable? or transmission problem? Or anything else? Thanks -Brock-

 

the only way an engine can rev up is if the throttle is stuck open.

pull the hose between the air filter and the throttle intake and see if anything got in there - you would think not cuz of the air filter, but it does happen.

it can even jam due to carbon buildup.

take the hose off and make sure the throttle butterflies are free to move with slight pressure.

it could also be the cable .. and again, you can test that with finger pressure at the intake.

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had same with 99sts at 105k..... go figure..... took apart what stomper is saying and sprayed down good with carb cleaner, reved engine good and sprayed again, and reved again.....the throttle and inner workings needed cleaned.... it worked!.....
rickyd