In my CCR1009-8G models the CPU temp is regulated towards 50 degrees.
When the ambient is like 20-25 degrees it can easily achieve this with the original fan.
Once the ambient rises the CPU rises to e,g, 58 degrees like you have.
So I would say there is something wrong, maybe fans in the wrong orientation.
No, the fans are oriented like they should - to blow the air out of the unit.
Like I said, it's rather hot in the room now, close to 30 I guess. When the ambient temperature was lower - the CPU temperature was also around 50, like you have.
Original fans also worked normally, if we are talking about the ability to cool the unit.
But they are a higher rpm fans (7000, as i recall), and have a very irritating sound.
That was the reason to replace them, not that they were unable to handle their work.
Noctua, on the other hand, are 5000rpm, and can achieve the same airflow at lower speeds with lower noise.
I guess the rpm numbers I get in winbox are not the real rpm, because the device has to be calibrated for 7000rpm fan.
And the real rpm is something like 5650x(5000/7000) ~ 4000rpm