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High Idle Alero 3.4

12-31-2007, 10:38 AM
My wife has a 2000 Olds Alero that recently has had a high idle issue. I haven't searched the threads yet to see if this topic has been brought up in the past however I decided to ask the question anyway. I have read a few articles on this issue so far and all lead to the IAC or a vacuum leak. It idles near 3000 at times. I was driving it one evening with my foot off the accelerator peddle and I was doing 45 mph. My Daughter also got a speeding ticket in it due to this issue. That we plan to fight in court with whatever information I can obtain on forums regarding high idle. Well, that's besides the point here right now. Any quick, logical answers/solutions regarding a high idle would be greatfully appreciated. Happy New Year!

12-31-2007, 12:04 PM
Welcome to AF!!

Your best bet is to look for a vacuum leak. This will cause the high idle condition you mention. It could be a broken vacuum line or a leaking intake manifold gasket. A broken or leaking line will be a much easier fix than a leaking intake manifold gasket. Also be sure to check the vacuum line to the brake booster as they can sometimes leak too. One final area to check is the throttle body to make sure it is not sticking in the open position. If your TB gets carboned up they can stick open causing fast idle.

12-31-2007, 01:00 PM
Based on your symptom I would not rule a bad IAC causing high IAC counts or one that is dirty/clogged with carbon. Try cleaning the IAC first with carb or throttle body spray cleaner, especially at the dish as shown in the pic below. Make sure you get the seat where IAC mounts to the throttle body too. Be sure to spray the spring loaded pintle with silicone lube. Also, check the electrical connector and make sure the PCM 5 volt low reference signal is good.

12-31-2007, 02:14 PM
Thank you....I will look at both situations. The Intake Manifold Gasket was replaced already under warranty. Hopefully that isn't the issue. Upon success...I'll post to let you know what the issue was and thank you...your replies are greatly appreciated. I had the IAC issue on my Mustang.....hopefully this is the issue here!!!

01-01-2008, 11:46 AM
Well....for starters....I took a look at both situations. The IAC was filthy. I am sure I will just replace it later on ( I did clean it for now). There was also a broken vacuum line that may have been broken upon completion of the Intake Manifole Gasket. It was the line to the PCV. Upon reinstalling the IAC and starting the engine, I heard a loud sourse of sucking air and traced it to that line. I will have to replace it later however for now I just used some silicone sealant. I'll let that cure and see what happens. Thank you all for the information. I'm a newbie here and sure do appreciate the quick and accurate responses....

01-01-2008, 04:47 PM
what should be the normal idle level????

my 2.4 idles like a 600 rpm's, is that fine?

01-01-2008, 06:05 PM
Correct me if I'm wrong but I think it should be around 800 rpm. I'm not too sure but that is where my wife's Alero seems to idle at and it sounds normal.

My issue with the IAC and broken vacuum line is solved....thank you!!!!! Now it's time for a power steering pump. I installed a used one and it was junk. New pumps are a month on backorder.

01-01-2008, 09:09 PM
what should be the normal idle level????

my 2.4 idles like a 600 rpm's, is that fine?

that is normal for 2.4 automatics 800-900 for manual 2.4 and 700-800 for 3.4l aleros

01-01-2008, 11:29 PM
okay good, because im just paranoid my car is going to break everytime i get in it

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