I was driving home the other day from school (yay no more finals) when I dropped out of 5th into neutral to slow down for the on ramp for the rest stop...as soon as the revs dropped from like 4,000 to 1,000, they suddenly jumped to 2K, then back to 1,5000, then up again to 2K, held at 1,500, then dropped down to around 600, back up to 1,100 and then stayed there till i shut off the car in a parking spot.....

later on at another rest stop, it happened again....

what is going on?

 

ya know mine does something similar but only when its cold outside (I think). It will go to 1,500 when I go to neutral and then drop down to 800-1,000 after a few secs. I have no idea what is wrong. Never mishifted either.

 

it doesn't sound too abnormal... it does it on my car too. However, mine drops to around 900 then to 1,200. Probably due to the radiator fan or accessory fan kicking in which raises the rpm. I don't know about 2,000 rpm though... but maybe your tach is off.

 

Sounds like the OBD computer is responding to some trigger. Have the codes run if it keeps doing it.

 

Mine does this as well!... I even pulled over and popped the hood to see if the fan was running one time. It wasn't, so I don't know why idle varies by several hundred RPM sometimes!?!..