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
, 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.
Chevy Impala Trans Won't Move After Engine Replaced

More Car Repair Help

Live Chat:
Engine question.

Mechanic: Go ahead.

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!