When you rev your engine during a cold start by accident or because you're a dumbass or maybe you're in a hurry...do your rpms get stuck after letting go of the throttle and even rise a bit on its own before falling back down?... mine has done it twice, both during cold starts. Wondering why it does that?? and on a scale from " red lining the rpms" to " putting an A8 in neutral while rolling to rev the engine at a prius," how bad is that for the car?
In all seriousness though should I not be worried about it as long as the engine isn't revved during cold starts?