Today a problem arose with the idle of my car. I was sitting in a parking lot waiting for someone and after my car sat for about 10 minutes I heard a click under the hood and my normal idle dropped down to an abnormal idle bouncing up and down from about 200rpm to 500rpm. I let the car run and about a minute of doing that it clicked again under the hood and the idle corrected itself and started running smooth again. Later the same day at home i decided to let my car sit in the driveway and idle to see if it would do it again. It did indeed do it again after about a ten minute idle(exactly the same as described above). Does anyone know what this may be or what to look for? Thank you for the help. My car has the 3.0 V6, auto trans.

 

do you have a stock intake or aftermarket? Basically it sounds like a vaccum leak. Which could be coming from anything from the intake pipe (stock or not) or vacuum lines around the intake manifold.

That is the most basic things to start with

 

I have checked all of the vacuum lines that I can find. Like I said there is a loud click then the idle problem starts, then after about 3 minutes it will click again and correct the idle. This process will keep going until I drive or shut the car off. Stock engine minus a cold air intake.

 

it sounds like it has to be something vac related, wether it is intake - manifold or what ever. Check EGR valve ect

Is the check engine light coming on or anything

 

The check engine light did come on for an 02 sensor just the other day. Do you think that may be related? I will replace it pretty quickly here in the next few days.

 

what bank o2. If it is the second o2 there could be something wrong with your cat. converter possibly. Not sure if that would cause your issue but a bad second o2 wont cause and idle issue.

The 1st o2 might cause an idle issue, not sure

 

I had the same problem, though slightly more extreme. The engine actually died. I found the culprit: dirty idle air control valve. It's designed to increase the flow into the intake when the compressor clicks on. If it's dirty it won't get enough flow increase. I also discovered that running the a/c in defog mode uses the compressor to help dry the air. This sounds like it's exactly what's happening to you.

To fix it I pulled the IAC valve and cleaned it out with some carb cleaner and dried it, then reinstalled it. Be careful when torquing down the screws, I broke one side tightening too much. Still attached though.

This dirty condition could also cause the o2 sensor to report a faulty condition. Might not be the case though, just a thought.

 

po301 code on ses light misfire in cyl 1 bad plug an coil changed both problem still exsist any solutions