I drove my 2000 Cavalier up to about 197,000 miles with the original engine and transmission never taken apart. It didn’t use any oil between changes and I still got over 30 mpg. I bought it with about 120,000 miles. The original owner was a friend who did regular oil changes. All the maintenance I ever did with the car was oil changes and lots of brakes and rotors. It was my driving school car. It needed a new AC compressor and radiator at about 150,000 miles. I’d still be driving it but the state makes us replace cars after 8 years or 80,000 miles, whichever occurs later. My current work car is a 2004 Cavalier with about 145,000 miles. The ecotec motor is much more powerful. The front end of the 2004 was squeaking a lot and we tracked it to a front right swaybar bushing. Not the end of the bar but the bushing closer to the middle. I thought it was a strut because it was very noisy. Yours may have the same problem. Try spraying lubricant on the bushings as they are difficult to replace. Not a lot of room to work in there. Check out this link to correct an oiling problem if you have the ecotec motor.
http://www.chevytalk.org/fusionbb/sh...hp?tid/219345/