Is the pinion gear shimmed correctly to the driven gear? I think that model has a slight gap. Try using a thin strip of notebook paper, crank it through the gears, and if it comes out looking like an accordion, you did it right. Any slits that punch through = too close. Too flat = too far away.
My original TRX6533 receiver could not run my engine sound box "noise maker", so I stole one from my friend's emaxx, #TRX6518, I believe, and that made it all work. This is my Rustler 4x4 we're talking about. Can you try a different receiver box? I am as surprised as you are , probably, hearing...
Is the receiver/transmitter compatible with your drivetrain? Can you try a new signaling system, transplant from another vehicle? The frequency/electrical ranges may not be compatible. I'm beginning to reach here, as all of my experience is in Traxxas. Good luck
Try a hard reset, there is a menu tree for that in the manual. My Stampede 4x4 used to hesitate, chug, and then let fly with full throttle. Then smoke came out of the body, illuminated by the headlites. The motor was hot enough to burn my thumbprint off. Got a new VXL motor and ESC under...