Have a 2002 Cavalier, 4 door, auto trans. It's been one of the most reliable cars I've ever had, and I've been driving since the early '60s.
But a few months ago it started acting up and I took it to my Chevy dealer and they didn't see anything. One day when the car was very warmed up it started to demonstrate the classic "slipping" signs of a slipping transmission. When it did, the speedometer would swing wildly as would the tach, and it sould seem like the engine is racing. If I take it verrrry slooooow, it might shift okay. Makes people behind me understandably impatient. It gets worse if the trans is under strain, like going up a hill. Going down hill, with some momentum, is usually not a problem, but where I am at in southern California, there are lots of hills, and this car now has a problem climbing hills. If I make it onto the freeway and get up to speed without a lot of starts and stops, or hill climbing, I'm okay. It got so bad last weekend that I had to pull over and call a tow truck to get me home. At that time, the engine would be racing, but the speedometer would not move. It's sitting at home now, and if I go home, it will start up fine, I will drive it to the store with no problem; but after it gets warmed up, the "slipping" will start, especially if I'm going up hill and/or try to "wind out" in each gear.
The car has 133,000 miles on it. I had the transmission serviced/flushed at 100,000 along with a tune up.
I know that this may sound like a transmission problem, but I can't help but feel that this is as much an electrical problem. Am I right? Any help would be appreciated; I need to get this fixed, because I'm sharing my wife's car, and we're about to start fighting.