Ebay 102mm throttle bodies. IAC passage whistle.

[JHPerformance]

Recently tuned an fbody with the 4bolt eBay chinese throttle body. I noticed upon startup the IAC makes a god awful screeching whistling noise until the IAC opens. I confirmed it IS coming from this air passage. I can block off the passage with my hand and it stops. I have tried changing IAC's out also, it is definitely in the machined out air passage. I chamfered the edges out and it seemed to help but theres still that unbearable whistle at first.

I was wondering if any other tuners have ran into this. Everything seems to work fine but that noise is intolerable. I recommended purchasing a name brand from the states. This is my first eBay TB, I was wondering if anyone has ran into any other solutions to this issue. Thanks!

[5FDP]

Stock airbox will make it quiet but that kind of what you have to deal with on a aftermarket intake setups and cheaper throttle bodies.

Same deal when people add air intakes to 3800's with mods, the noise becomes much louder at cold start up. Pretty much like a shove on concrete with a whistle behind it.

[Area47]

Recently tuned an fbody with the 4bolt eBay chinese throttle body. I noticed upon startup the IAC makes a god awful screeching whistling noise until the IAC opens. I confirmed it IS coming from this air passage. I can block off the passage with my hand and it stops. I have tried changing IAC's out also, it is definitely in the machined out air passage. I chamfered the edges out and it seemed to help but theres still that unbearable whistle at first.

I was wondering if any other tuners have ran into this. Everything seems to work fine but that noise is intolerable. I recommended purchasing a name brand from the states. This is my first eBay TB, I was wondering if anyone has ran into any other solutions to this issue. Thanks!

I ran into an idle issues with cheap TB's as well. noise, and other crap. Only time they did not have problems was wot.

[mbray01]

in my experience with these, is
1 smooth the opening and exiting portions of the iac circuit,
2, even though it is frowned upon, with the chinese throttle bodies they almost always have to have the blade drilled to work correctly, which will lower the dependency on the iac, and also reduce the whistle which seems to occur more at high iac positions

The good throttle bodies I never have to drill, but I seem to always have to drill the ebay ones for one reason or another