Q: When my car is at idle in park or neutral the Intake Air Control Valve fluctuates, causing the RPM's to do the same.

asked by on

When my car is at idle in park or neutral the Intake Air Control Valve fluctuates, causing the RPM's to do the same ranging from 800-1200 rpm's. If I unplug the IAC valve it stays at a solid RPM. Every sensor I've used had the same activity. So the PCM is making it fluctuate, what could cause that?

My car has 240 miles.
My car has an automatic transmission.

Hi there. It sounds as though the idle air control valve (IAC) may be sticking. It is not uncommon for carbon to build up in the valve, the computer will try to overcompensate to correct the slow reaction inside the IAC, and therefore the idle will fluctuate. It would be best to observe the commands from the PCM with a scan tool if you cannot physically see if there is carbon build up. A certified professional from YourMechanic can come to your car’s location to diagnose the idling problem and assist with repairs.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. When my car is at idle in park or neutral the Intake Air Control Valve fluctuates, causing the RPM's to do the same.

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Q: Blown engine

Check you dipstick to make sure that the proper amount of oil was installed. It's possible that someone forgot to re-fill the engine oil. It could also just be a coincidence that the Check Engine Light came on after the...

Q: Very rough idle goes away at speed. Can it be the cam solenoid?

Hey there. This may be related to a dirty or failing idle air control valve. The idle air control valve monitors the air intake as it is mixed with fuel prior to being injected into the engine at low speeds...

Q: Q: Needing transmission serviced.

Hi there. Your check engine light can come on for any number of reasons. If the vehicle is running fine and it just came on it may be as simple as a loose or faulty gas cap. If the vehicle...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...