As the title says I
m experiencing intermittent idle surging but it only happens after the engine is warmed up and only when the car is in park.Idle will creep up and peak at 1,500 rpm and then go back down to 700 rpm,it takes about 15-20 seconds for a complete cycle (from 700 rpm up to 1,500 rpm and back down to 700 rpm) It doesnt always do it when the engine is warm but when it does do it it usually lasts for several minutes.
never does it when the engine is cold.
never does it in neutral or any other gear,only in park.
t know if this is related but Ive also noticed that that the transmission won
t shift from reverse into neutral but it will shift from drive into neutral.If I shift from reverse into neutral the car thinks its still in reverse and continues going back.(car has a floor mounted shifter between the front seats)
I thought it might be the idle air control valve but wouldn`t the idle continue to cycle,like that, even if the car is in gear?