Ive been a self-proclaimed master of boost leak testing and finding even the most inconspicuous boost leaks for a loooong time now. I keep my tester in my trunk and usually test once or twice a week just to be sure Im on top of them.

My car has been boost leak free for several months now. The system holds air perfectly. Until I just tested right now.

I fill the system up with air and I hear a loud woooossshhh and its all gone within about 5 seconds, the noise is somewhere back by the intake manifold/throttle body. My throttle body has milspec hi pressure shaft seals, which I installed back in August and have had 0 issues with.

The weird thing is I am having 0 drivability issues. The car pulls hard as hell, idles normally, and there are no vacuum issues. All of the vac lines are on and secured.

I can not figure out for the life of me where this leak is. I sprayed boost leak test fluid (soapy water ) everywhere I could reach and see, and saw no bubbles. Still, the air is escaping somewhere back by the intake manifold. I dont see how its making its way past the throttle body, yet the noise is somewhere back in that area.

Nothing has changed on my car since the system used to hold air just fine, and now all of the sudden it isn't. What could be causing this?

 

Bump/update

I am going to check the coupler tomorrow. I had recently had my entire upper section of upper intercooler pipe off to tighten up my alcohol nozzle to address a boost leak there. When I reinstalled the pipe, I aligned it on the throttle body coupler differently than I previously did; I had the pipe in further previously and now I made it so that the pipe was a bit further out sort of like this o| o and then I made it o |o (the circles are the ends of the coupler and the line is the pipe)

So what I think happened was the air was traveling over a part of the coupler that had a tear in it, and before when I had the pipe further in the coupler closer to the throttle body, the air never had to go over that part of the coupler that had the tear.

 

Let us know if that was it...

 

injector seals?

 

No I found it, its one of the vacuum lines that runs off the throttle body behind the intake manifold. The ones from the throttle body themself arent the problem because I secured those a while ago with zipties.

The hose Im having a problem with is the continuation of the throttle body hose on the back of the intake manifold.

Its the yellow striped black hose, its no longer connected to wherever it is supposed to be connected to at the other side of the intake manifold and I can not find the nipple that it is supposed to connect to, I cant feel or see where it should go.
it is still connected on the nipple that is closest to the intake manifolds opening on the driver side, its the passenger side of the line that is off, farthest from the throttle body.

Could anyone guide me to where this hose is supposed to reconnect to under the rear of the intake manifold? its relatively long, it stretches almost to the end of the intake manifold.

 

Here it is, I found it finally. Sneaky little thing.

 

glad u got it. (sorry to TJ, but didnt feel like starting a thread for this ?, and were on topic, here)

well, I went to go make sure all of my vac line are attached... And noticed I have a nipple/attachment for a hose (on the throttle body) right under the lil accelerator lever (that u can use to give it gas from the engine bay) like that technical talk... facing the engine bay, on the bottom side of the TB, but in front, quite visibal...
is there supposed to be a line there???

sven: where exactly is the nipple located? Cant really tell. thanks

 

That nipple/sensor is behind the block, under the 3rd or 4th runner of the intake manifold closer toward the passenger side of the car.