1999 Chevy Impala 3800. Check engine. Checked to see if everything was plugged in knock sensor ect. Question = Helping a friend with his car, somebody replace the motor then right after that the transmission did not shift at all.I change the motor again because the one they put in was junk. It is good in drive and good Reverse. Tried manual shifting no luck on any shifts. I believe I got it to shift one time manually shifting from first to second possibly. Checked and recheck all spark plugs, also checked all fuses.
Answer: Not sure what the problem with your Impala is. You say after the first motor was replaced the transmission did not shift at all. Then you replaced the motor again, and now it is good in drive and reverse. Is this the same condition? Do you mean it wont upshift by itself? But, you say it is fine in drive and reverse.
If you mean that when you put the transmission into low 1, it will not shift when you go to low 2 then overdrive, then drive, that would have nothing to do with an engine replacement. That problem would also have nothing to do with electrical plugs or anything else electrically inside the transmission.
Not being able to manually shift it means there is a mechanical problem inside the transmission. Possibly a valve body problem with a stuck manual valve or some other component like a low/reverse roller clutch.
I Just bought a 2004 Chevy Impala SS. When in park if I rev the engine it act like rev limiter a about 4000 rpm. Thanks for taking my question. I have gone over everything I can, wires, plugs, air filter etc. doesn't do this in drive. Is this normal for these cars?
Yes, this is a rev limiter. It only limits RPM in park and i believe neutral too.
Ok, great. I just went for a test drive to confirm. Rev limiter in park and neutral. When car is rolling, no rev limiter in neutral. Thanks for the help. My first Chevy. Have Toyota and older ford. Thanks again!