# iac location



## Angry_Pig (Nov 6, 2011)

I searched the forum and couldn't find a thread 
Could someone help me out to show me where the iac sensor is at on a mk4 aww 1.8t. Like a picture or something I'd greatly appreciate it


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## Neezy13 (Jun 1, 2011)

Its in the intake manifold just after the throttle body.


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## Angry_Pig (Nov 6, 2011)

Thanks very much neezy13!!!


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## Vegeta Gti (Feb 13, 2003)

IAT sensor

Sent from my SPH-D710 using Tapatalk 2


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## Chickenman35 (Jul 28, 2006)

IAC = Idle Air Control (Which may not be used on a 1.8T. At least it's not on an AEB ) 

IAT = Intake Air Temperature sensor....as shown in the picture.


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## Neezy13 (Jun 1, 2011)

Good catch guys. I assumed he meant IAT sensor because I don't think 1.8t's have IACs. :beer:


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## kamahao112 (Nov 17, 2007)

Neezy13 said:


> Good catch guys. I assumed he meant IAT sensor because I don't think 1.8t's have IACs. :beer:


 they do it built into the throttle body


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## Chickenman35 (Jul 28, 2006)

kamahao112 said:


> they do it built into the throttle body


 Not an an AEB. On an AEB ( DBC ) the idle control is controlled by a small stepper motor, which controls the idle speed. It only allows for a few degrees of throttle movement...main throttle control is by cable of course. Source Bently and Ross Tech. I'll provide linky if you wish. 

OP has an AWW, so I could be wrong about that on the later models.... DBW may also have idle speed controlled by the stepper motor. 

BTW, the stepper motor is not considered an IAC per sae. An Idle Air Control valve ( sometimes called Air Bypass Valve ) is a solenoid that allows a small amount of air past the throttle blades to adjust throttle speed. I not sure that they are used with later DBW systems ( in general..not just VW/Audi ), because the stepper motors can do the job effectively by themselves.


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## kamahao112 (Nov 17, 2007)

Chickenman35 said:


> Not an an AEB. On an AEB ( DBC ) the idle control is controlled by a small stepper motor, which controls the idle speed. It only allows for a few degrees of throttle movement...main throttle control is by cable of course. Source Bently and Ross Tech. I'll provide linky if you wish.
> 
> OP has an AWW, so I could be wrong about that on the later models.... DBW may also have idle speed controlled by the stepper motor.
> 
> BTW, the stepper motor is not considered an IAC per sae. An Idle Air Control valve ( sometimes called Air Bypass Valve ) is a solenoid that allows a small amount of air past the throttle blades to adjust throttle speed. I not sure that they are used with later DBW systems ( in general..not just VW/Audi ), because the stepper motors can do the job effectively by themselves.


 thats what i was referring to ... you just explained it with detail .. so if it were like a obd1 vw or a honda or sr20 rb25/26 .. they all the idle control valve totally separate from the throttle body .. but in the obd2 vw and up the idle is controlled solely by the throttle body and ecu so there for to ME its built in .. just the easiest way to explain it... ether way you say it they all do the same thing ...make the car idle!


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## Chickenman35 (Jul 28, 2006)

kamahao112 said:


> thats what i was referring to ... you just explained it with detail .. so if it were like a obd1 vw or a honda or sr20 rb25/26 .. they all the idle control valve totally separate from the throttle body .. but in the obd2 vw and up the idle is controlled solely by the throttle body and ecu so there for to ME its built in .. just the easiest way to explain it... ether way you say it they all do the same thing ...make the car idle!


 Yep....gotcha :beer: Just wanted to make it clear for the OP, so that if he was trying to find an actual Idle Air Control Solenoid Valve he could stop :banghead: against the wall. 

I can be a bit "Anal Retentive" at times :laugh: :beer:


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## Angry_Pig (Nov 6, 2011)

So I just have to get a new throttle body yay lol where can I find one of those suckers at haha


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## Chickenman35 (Jul 28, 2006)

Angry_Pig said:


> So I just have to get a new throttle body yay lol where can I find one of those suckers at haha


What exactly is the problem that you're having with your car? More details and we might be able to save you some money. IE: Inconsistent idle is usually due to hidden vacuum leaks. Throttle Body Adaptation ( easy to do ) may have to be done if battery was disconnected.


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## Angry_Pig (Nov 6, 2011)

Its hard to explain but like if I'm cruising normal speeds and what not then I come to a stop sign and throw it in neutruel it wants to rev its self up to 1k then back to normal idle


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## Chickenman35 (Jul 28, 2006)

Angry_Pig said:


> Its hard to explain but like if I'm cruising normal speeds and what not then I come to a stop sign and throw it in neutruel it wants to rev its self up to 1k then back to normal idle


Normal idle *is* around 1k ( actually 840 to 890 rpm when hot ). Sounds like you need to do a TBA ( Throttle Body Adaptation ) and do a pressure test to find vacuum leaks. VW/Audi's are notorious for vacuum leaks. Clean the Throttle Body with a commercial TB cleaner as well. That can make a huge difference.

I think you're on the wrong track on looking to "replace" the TB. :beer:


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## Angry_Pig (Nov 6, 2011)

Its hard to explain but like if I'm cruising normal speeds and what not then I come to a stop sign and throw it in neutruel it wants to rev its self up to 1k then back to normal idle


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## Angry_Pig (Nov 6, 2011)

Thanks chickenman.Friday I am replacing the intake and exhaust manifold gaskets just to be on the safe side.and I'll do those suggestions also thanks man


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