# IACV problem

**URL:** <https://forums.speedlife.net/t/iacv-problem/237668>\
**Category:** Shift518 Automotive\
**Created:** [July 7, 2008, 3:53pm UTC](https://forums.speedlife.net/t/iacv-problem/237668 "2008-07-07T15:53:43Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![JTizzleCivicSi](https://avatars.discourse-cdn.com/v4/letter/j/a5b964/32.png) [@JTizzleCivicSi](https://forums.speedlife.net/u/JTizzleCivicSi)\
**Post date:** [July 7, 2008, 3:53pm UTC](https://forums.speedlife.net/t/iacv-problem/237668/1 "2008-07-07T15:53:43Z")

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I have a 99 civic si and had a question about my idle air control valve. I’m throwing check engine code P0505, and my car idles high at some times  
with rough hesitation after the clutch grabs. I was wondering if I need to replace the whole valve, or if just checking for vacuum leaks and cleaning it would work???

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**Author:** ![toolow69](https://avatars.discourse-cdn.com/v4/letter/t/ac91a4/32.png) [@toolow69](https://forums.speedlife.net/u/toolow69)\
**Post date:** [July 7, 2008, 5:16pm UTC](https://forums.speedlife.net/t/iacv-problem/237668/2 "2008-07-07T17:16:19Z")

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if its throwing code for it than replace it. u can get it cheap. if not clean it out with brake parts cleaner

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**Author:** ![dc2nick](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/dc2nick/32/6289_2.png) [@dc2nick](https://forums.speedlife.net/u/dc2nick)\
**Post date:** [July 7, 2008, 6:34pm UTC](https://forums.speedlife.net/t/iacv-problem/237668/3 "2008-07-07T18:34:19Z")

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just replace it to prevent it from happening again

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**Author:** ![crAppAchic0](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/crappachic0/32/6306_2.png) [@crAppAchic0](https://forums.speedlife.net/u/crAppAchic0)\
**Post date:** [July 7, 2008, 9:39pm UTC](https://forums.speedlife.net/t/iacv-problem/237668/4 "2008-07-07T21:39:10Z")

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If it’s the same general setup as the ‘older’ IACV’s- and you’ve done anything to the radiator or cooling system in general- you can get an air bubble in the coolant lines running to the IACV, and it’ll throw off the temperature reading for the thermoplastic (again, thinking of the ‘older’ ones) - and you’ll get a idle surging, maybe more. I’d say bleed the air out - if that’s the problem. Then check for vacuum leaks, etc. All else fails, get a new one. Not sure how much they actually are, but at some point, the labor’s not worth the cost of the replacement part… :headbang

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**Author:** ![Hang\_Your\_Cross](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/hang_your_cross/32/6381_2.png) [@Hang\_Your\_Cross](https://forums.speedlife.net/u/Hang_Your_Cross)\
**Post date:** [July 8, 2008, 2:39pm UTC](https://forums.speedlife.net/t/iacv-problem/237668/5 "2008-07-08T14:39:22Z")

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try cleaning it out first with brake clean. on my old car it happened one time, i took it out and cleaned it and it was fine ever since. the sensor is located on teh back of the intake manifold next to the throttle body. it’s two 10 or 12mm bolts and then two coolant hoses attached to it…

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**Author:** ![Fn\_Skanks](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/fn_skanks/32/6308_2.png) [@Fn\_Skanks](https://forums.speedlife.net/u/Fn_Skanks)\
**Post date:** [July 9, 2008, 3:27pm UTC](https://forums.speedlife.net/t/iacv-problem/237668/6 "2008-07-09T15:27:31Z")

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+1  
for cleaning it out with brake clean/ carb cleaner. there is always a bunch of carbon gummed up in the idle motor. worse case scenario, just replace it.