Chevrolet: 1991 chevy cavalier, chevy cavalier, hi psi

Question
I just purchased a 1991 chevy cavalier 4 door with a 3.1L 6 cyl engine with auto transmission. It only has 140 000 kms on the oddometer. The car ran great on the test drive but now that i have it at home its a bit rough. It drives great but its pretty rough at idle. I also had a problem with the transmission. When i put the car in reverse and steped on the accelerator the car reved loudly as if it were in neutral but it did not move.... I put the car back into park and then back to reverse and then the reverse worked. This actually happened three times already. The oil gauge is also pretty high, does this mean the engine is about to die on me? What should i do to correct the rough idle? Is my transmission dying on me? Thanks for the help. Aaron

Answer
Arron;
  OK  first off- check the tranny fluid, if it is not a reddish color  change the fluid and filter in the transmission. as far as the rough idle , when was the last tune up ? , try a can of gas treatment and a can of dry gas. and the oil if it is in the HI   psi area thats good  it is the low or no oil psi that is bad. so run  a tank of
some good gas in it with the gas tank treatment and see if that helps you   ok
Roger   W.