Hey I have a 2003 Mazda 6i (4 cyl). And almost every time I start it up the rpms jump to 2000 and stay there till I shift into gear. The only exception is when it had just been running and i turn itback on again right after.
If anyone know ANYTHING it would be greatly appreciated. If its bad for the car or if it means a nut is loose or the whole thing is about to explode whatever. Any info

 

Sounds like you have auto tranny. The rpm should drop after the engine is warmed up a bit, 20-30 seconds in summer. You might also try to blip the gas a little to kick the engine out of fastidle.
Good Luck.

 

def. warming up, mine does the same, you want it to do this!