The reason I am doing a boost leak test in the first place is because I recently bought the car and just installed a wideband gauge and running rich (10.0) at wot. Anyways can someone tell me what this is? I know I have air leaking at the biss screw but I also have air leaking from here and dont know what this is called or if this is common? btw I have already replaced the tb seals with mil.spec.

 

Thats your IAC

 

No that isn't, that's something else. It was only on a year or two of the throttle bodies, on the back side of it right? The IAC is an electrical module that has a harness plug in to it. It's the question mark piece right? That I think is the backside of the throttle plate shaft opening...I think. I leak tested a friend's RS and it also had a leak there. It was a couple years ago but I did something to stop it...if I recall there are a few small pieces in there so you have to be careful when you open it not to lose any.

 

yes, this is the question mark piece that you labeled in your picture 05blue8. So I should remove the throttle body and take it apart? Anything I should order to replace it with like a seal or anything?

 

That's the back side of your throttle body shaft. Your seals are bad.

 

No its not. Sorry I looked at the picture with the question mark too quickly its actually below that, HERE

 

That's the coolant jacket for your IAC.

 

whatever its called its causing a boost leak.. how should i seal it? Does anyone else have this problem?

 

When I search online for an iac coolant jacket nothing comes up.. Anyone else have info about this leak I have?

 

This seems like a dead thread, but I have the same problem. Any update on this??

 

I used gray permetex silicone, worked fine for me.

 

Is it a dead end hole? Nothing connects to it? I threaded mine, basicly put a plug in it with some teflon tape. Thats if you want to go that far

 

That plug has what looks like a small flapper inside, with a spring that limits its rotation. I have no idea what it does, I just wanted to get the leak sealed up.
Well the o-ring that seals that plug was stiff and worn. I replaced it with a thicker one I found, really had to struggle to get it to fit. Didn't get to drive the car much but it seems to have done the trick.

JCG

 

silicon does the job

 

That's the access port to the bi-metalic strip to control course idle speed. I think it's acted on by the coolant flow through the throttle body. As the water heats it the valve closes up to reduce TB by-pass air. Mines leaking too.