Spool overdrive chatter when stopped. Park, reverse or drive. If car has no throttle added it'll chatter and run fuel rail psi up. Adding throttle stops it for a few seconds then it shoots psi up again.
When I am idle after driving, in park, manual mode, drive, or reverse, my fuel rail psi goes from 800 to 2.1k+ and makes a terrible chattering noise. It is similar to the noise on startup but seems even worse. If I give it gas or wait about 6 seconds, it'll go back down to 800 and sound normal again. Then about 8 seconds later it comes on again and the cycle keeps repeating itself.