When driveing my carit run all of the gears are well 'till it get hot' then she stop and would not move then i trun off the car ' and start it up agian; can you tell me what happening

HOW many miles on the engine (REDUX)?/? 3.5L V6 engine? or 2.5 or the Diesel??????????
I'd have to drive IT to know.
let me guess the mech tested the car and it ran OKAY, so says" I can't find the problem. " ( what else")
you never told what the engine does , when it does fail and is Intermittent.
just that engine is ON. (runs)
and car does not move, sometimes.
what matters first, only when it fails, is does ENGINE RPM RISE fast and high when it fails.
see how that works, if it did the transmission is slipping (CVT are not fun here)
2500 RPM when it fails, right foot in to the throttle pedal this is transmission slip (failure)
if RPM are low failed, that is engine failure. (lean burning) or EGR stuck on or other problems , many.

lost engine power. has lots of causes; but this is gas(petrol) answer.

1: engine failing ,top cause , VVT or that chain loud noise? ?
2: spark plugs bad over 100k miles, (not diesel)
3: fueling bad, even bad fuel, or goes lean due to fuel pressure loss.(low) fuel pump weak?


driveLine choices day1, new not told gen 2, 2007 car.

Gasoline:
2.5 L QR25DE I4
3.5 L VQ35DE V6 <<<, seen in USA is it?
Diesel:
2.5 L YD25DDTi I4 no 2010 first

TransmissionCVT (Gasoline)

6-speed automatic (Diesel) 2010 up/

try new spark plugs and spark cop boots? 100k service point is is. and gaps will be way off ,when old

boots are here.

checkout NGK here. on COP boots x6

https://www.rockauto.com/en/catalog/nissan,2007,murano,3.5l+v6,1434436,ignition,spark+plug+/+ignition+coil+boot,10150

not a vapor lock
problem EVAP system
run the fault codes to determine the exact faulty sensor

Hate to say it but the gears were not in the correct position when you put it together.

You don't say what kind of car it is but you likely have a bad shift solenoid which will need to be replaced. The car shifts down to limp mode so you can drive it slowly, Once it cools off, things reset, for awhile and then will act up at odd times.

run fault codes and check for ambient air temperature sensor fault and check gear box for sensor/servo problems

Check fluid level. In park. With engine running. If fluid level is ok it maybe internal trans.

Sounds like you need to have the bands /gears adjusted to prevent the slipping.

check fuse ,wiring ,and connections ,check for proper fan operation,clogged radiator ,water pump and belt and for possible bad sensor

did it change gears before you change the motor

did you get your radiadator checked?