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Idle air control valve

if it is not fixed, what is the worst thing that could happen?

What is it doing now? The worse thing is that the idle speed cannot be controlled so either it will be too high or it will die all the time. The IAC is a pretty reliable device, but won’t work if it is not given all the signals it needs. More often than not, it is something else, so tell us why you think it is bad. What are the symptoms? Do you have a check engine light? Have you had the code read? What is the code (P0xxx).

Also, what kind of vehicle?

i have a crystler sebring 05. everytime i turn it on i need to give it some gas to stay on. but once im driving its ok. iv had it over 2k RPm sometimes. i do have a check engine light on. i had the codes pulled but the guy never told me the codes and said it was my Idle air control.

Sounds about right. Just replace it - it shouldn’t cost that much if I recall.

how much do you think? the part is like $80

Cost of the part should be it. It’s an easy replacement, if I recall. Just do it yourself.

It is very likely NOT the IAC. The IAC gets its commands from the computer, but the computer only sends the commands if it knows your foot is off the gas. If the computer doesn’t know this, then it doesn’t send any commands.

The computer gets its information from the throttle position sensor (TPS) or the idle position sensor (IPS). Now if something is blocking the throttle from fully closing, such as the throttle stop screw which some mechanics still think is an idle adjustment screw, the computer will think you are still on the gas and will not send any signals to the IAC.

A dirty throttle body could also keep the throttle plate from closing enough to trigger the idle position signal. A vacuum leak will also cause idle speed problems and is actually most often the cause of an idle speed problem.

There are no codes for an IAC. The only codes for idle speed are P0505, P0506 and P0507. While the IAC is listed as a possible cause, it is not the primary thing listed, but if you get your codes read at an auto parts store, it is the first thing that involves a part they can sell you.

deffinitely check the throttle body for carbon build-up first, as this is the most common cause of idle problems , especially when cold. ifyou can get the car to idle ok, and then turn on the lights and ac, what happens? if the engine slows way down, it could be an inoperative iac. if it stays the same or increases slightly, then the computer has control, and its probably mechanical, such as carbon in the throttle body or a vacuum leak…

when i start the engine its slow to begin with. i dont notice any change in RPM’s when i use the lights or the AC. once i start driving, everything is ok. just idles lower then normal.

It sounds to me like the IAC is doing its job. Turning on the AC does not always result in a higher idle speed, in fact, ideally the idle speed does not change at all. In a perfect system, when you turn on the lights or the AC, the computer commands the IAC to add just enough air to maintain the idle speed at the same RPM. If it wasn’t working, the idle speed would drop.

Take your vehicle to a place like AutoZone and ask them to read the code(s). They should give you a cash register print out with the code at the top and the possible causes and remedies. Ignore all but the code, post it here. It will be in a format Pxxxx with the x’s being numbers, i.e. P0506.

Also, what is your idle speed? These two pieces of information are critical to helping you.

The most common problem with Chrysler products not idling right is dirty battery connections. Every time you try to start a Chrysler with dirty connections, the computer clears and has to relearn again. One tell tale sign is to scan it and look at ignition cycles. If there is a very low number, like single digits then the computer is being cleared on startup.