Idle Air Control Valve Making Loud Racket What Does This Mean?
05-19-2010, 06:56 PM
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Car: 1987 GTA Vert & 1991 GTA 5 Speed
Engine: 87 GTA-L98 91 GTA LB9
Transmission: GTA-700R4 & GTA T5
Idle Air Control Valve Making Loud Racket What Does This Mean?
First hot day I had my car out, GTA Vert w/ 5.7 TPI. Things started off good but then the car started running hot.
I was running down some issues with my fans that quit working. Did the diagnostic per the service manual and my fans are indeed dead. Both died which seems very odd to me. But during the process I had to ground my ALDL as if I were searching for trouble codes. When I did this I heard a clicking sound. It was a rapid successive clicking. Searched around and finally just unplugged my IAC and it stoped. I checked to see if it was plugged in properly and yes it was.
Turned off ignition plugged it back up turned ignition on (didnt crank up car) as if checking for trouble codes and clicking started again.
I never noticed this before. Is this normal or should I be ordering a new IAC valve?
I was running down some issues with my fans that quit working. Did the diagnostic per the service manual and my fans are indeed dead. Both died which seems very odd to me. But during the process I had to ground my ALDL as if I were searching for trouble codes. When I did this I heard a clicking sound. It was a rapid successive clicking. Searched around and finally just unplugged my IAC and it stoped. I checked to see if it was plugged in properly and yes it was.
Turned off ignition plugged it back up turned ignition on (didnt crank up car) as if checking for trouble codes and clicking started again.
I never noticed this before. Is this normal or should I be ordering a new IAC valve?
05-21-2010, 05:10 AM
#2
Re: Idle Air Control Valve Making Loud Racket What Does This Mean?
Perfectly normal. Whenever you jump the A-B terminals at the ALDL and turn the key on, your IAC motor will click like that indefinitely. Whenever you turn your ignition key on without being in diagnostic mode, the IAC will run until the pintle is all the way seated, then it'll stop, but when you have the A-B terminals jumpered, it just keeps running, even after it's all the way closed. The reason it does that in diagnostic mode is so you can adjust the minimum idle speed screw on the throttle body. If you read the tech article here on how to reset the IAC and adjust minimum idle speed, it explains the whole deal.
05-21-2010, 06:33 AM
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Car: 1987 GTA Vert & 1991 GTA 5 Speed
Engine: 87 GTA-L98 91 GTA LB9
Transmission: GTA-700R4 & GTA T5
Re: Idle Air Control Valve Making Loud Racket What Does This Mean?
Perfect explaination! Thanks.
05-22-2010, 08:20 PM
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Car: 89 IROC-Z
Engine: L98 5.7 liter
Transmission: TH700r4
Axle/Gears: limited slip 3.23
Re: Idle Air Control Valve Making Loud Racket What Does This Mean?
I was glad to come across this post because I recently found out that a battery drain that would completely drain the battery in 4-5 days was being caused by the IAC, or so I think. With the key not even in the ignition and everything turned off, I could hear what sounded like voltage being applied to the IAC motor or the pintle going back and forth. I ordered a new IAC, but now I'm not sure whether its the IAC or my ECM? Any thoughts or ideas? And were you having battery drain issues also?
05-22-2010, 09:40 PM
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Car: 1987 GTA Vert & 1991 GTA 5 Speed
Engine: 87 GTA-L98 91 GTA LB9
Transmission: GTA-700R4 & GTA T5
Re: Idle Air Control Valve Making Loud Racket What Does This Mean?
Never had any problem with power drain. Hopefully one of the other guys will chime in.
04-26-2015, 10:16 AM
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Re: Idle Air Control Valve Making Loud Racket What Does This Mean?
I was glad to come across this post because I recently found out that a battery drain that would completely drain the battery in 4-5 days was being caused by the IAC, or so I think. With the key not even in the ignition and everything turned off, I could hear what sounded like voltage being applied to the IAC motor or the pintle going back and forth. I ordered a new IAC, but now I'm not sure whether its the IAC or my ECM? Any thoughts or ideas? And were you having battery drain issues also?
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