Since replacing my thermostat today and bleeding the system well. My idle when in park just blips from 1500-2000 constantly.. My icv is whistling so I'm not sure if it's on way out?
Did you run the engine running with not radiator cap after refilling the radiator? is the IDLE going down when the engine is hot? You might have a faulty Temperature Sensor.
PCV vaccum leak will cause idle up and down so I guess any vaccum leak in that area, would be similar. Try unpluging the icv to see if that is the cause.
I bled the system with the engine running and no cap. Could be where is the temp sensor located it it the one near the stat housing just in front going into the block?? With regards to revs comments just tge plug onto of the icv yeah?
You may have dislodged a plug or wire to the sensors on the thermostat housing, but if its idling like that its more than likely a vacuum hose off after the throttle body.