2012 Impala makes a loug rumble, rattle sound when I start it up and put it in gear

Great question.
PRNDL (is the cable good both ends) shifer>?
R good
L good?
Drive , selected and 1st gear car will not move ?
or 1st gear car moves good but will not up-shift.
1,2,3,4 gear. 1st slips or works??????????????
name 4T60 (transverse 4speed box) GM./
DIY?
check fuse first
scan the PCM (the PCM has TCM) the TCM tranny brain and if TCM is not happy it tells you why
so all carsChev 1992+ must be scanned, first.
the 4t60E box is electronic shifted. scan it.
what is miles on car.? 100k,300Kwhat?

causes are vast, (ever see inside any A/T box)
the next test in the book is pump pressure test
PRNDL

Hi Kai:
The first things that I would check would be the drive sprocket and chain tension.

Sounds internal to me. Fifth gear bearing locked up. I assume it is manual(unless the bearing has welded itself to the shaft and case)? These aren't hard to rebuild. Automatics are a bit trickier. Either of them have to come out.

If the wheel is out of alignment so bad that it is noticeable. Then I would be checking the suspension ball joints and the wheel bearings. If the wheel is not held true when running then the cv joint will be binding up and generating the noise.. If you are not savvy to this I suggest you put it on a truck and get it to a workshop before you do more damage .

Sounds like theres no 1st gear. Have you put the shifter in 1 and seen if it went, if so try 2-3 if it still accelerates slowly its probally stuck in 1st or 2nd gear, when it goes in to the 3 rd gear it will accelerate normally, also in 4th (OverDrive)

indicates detonation or spontaneous combustion in the cylinders
cause is from lean mixture , incorrect timing, faulty knock sensors
run the fault codes to determine the faulty sensors

It sounds like you have a blown throw out bearing for the clutch operation. Fix it soon or you'll do a whole lot more damage to the drivetrain.

Replace the transmission.

The throw out bearing could cause these isues, however I would look else where before doing anything about that. A throw out bearing can be "bad" for a very long time without causing any issues other than annoyance. Is this a cable operated slave cylinder or a hydraulic? If Cable you can adjust the throw of the pedal to take up any slack that will be made from there. Your problem sounds like your not getting enough clutch pedal throw, is there allot of play in the pedal? A simple test you can do is with the car off pointing down hill (key on so steering wheel is unlocked) With the car in gear, depress the clutch pedal slowly untill the car begins to roll. If allot of travel is required then you know that your not getting full use of your clutch pedal. A Broken shift or stretched shift cable could cause this issue as well. I would start simple and work your way up. If a hyd. system it is self adjusting i would check for full fluid in the resevoir as well. Let me know how you make out and we can trouble shoot from there.