Hello all, I am performing a boost leak test for the first time. Have the tester and plug in the bottom IC hoses and airbox removed. When trying to pressure use the system, it won’t hold any pressure so I have a big leak somewhere.
Sounds like it is coming out of the are where the airbox connects in?
If that is the case, where do I start to address the leak?
Thanks.

 

yeah I think the way you have it hook up your just blowing air up your intake. put one on each inlet to your turbos.

 

don’t think that’s the case. Deejay Markski directs you hook it up this way.

 

must have misread what you wrote. there is a gasket at the intake to the throttle body. it is like a formed o-ring. mine leaked at over 10 psi. maybe yours is worse. it is a bad joint as there is no standoffs on the joint just and o-ring getting clamped down on. it's hard to see it and mine was bad enough it would just blow the soapy water off and and not make bubbles. it is a common failure point.

 

its been several years since i've done this. but seem to remember testing at the turbo outlets as that will encompass the whole system sealed incl the y-pipe with the ic hoses "sealed" with those homemade things. this yt clip should help. the guy even name checks markski for the tips.

 

[QUOTE=jcc0016;4899636]Hello all, I am performing a boost leak test for the first time. Have the tester and plug in the bottom IC hoses and airbox removed. When trying to pressure use the system, it won’t hold any pressure so I have a big leak somewhere.
Sounds like it is coming out of the are where the airbox connects in?
If that is the case, where do I start to address the leak?
Thanks.[/QUOTE

If it's connected right, and holding no pressure, you should be able to hear a mass exodus somewhere. Sometimes running your hand over engine bay, you can feel the airflow. Spray bottle with dishwasher soap a good idea also, and will likely come into play later, a leak of this size should be very obvious, if holding 0 pressure. Just leave the air hose connected at like 20 PSI, and let it flow while you look around.

 

just to take a step back. did your boost gauge register any boost while driving? if the leaks that bad with the test setup in I would imagine you would never get to 0.6 bar. if you did get decent boost then maybe you do have something with your test setup not exactly right.

 

I did see boost to 0.4 and I have a COBB tune, so I knew something wasn’t right.

 

Your F-pipe might have a huge crack in it and not holding any pressure, or the left intake manifold might also have a crack from someone lowering the engine too low. Like JSBear stated, place your hand around that area, spray with water, and see what is causing the leak.

 

Thanks. I had pulled the f pipe when I replaced the DVs and inspected for crack and hadn’t seen any.
I was not aware of an intake manifold crack possibility. How does that happen when lowering the engine?

 

leak. Turbo's will work harder to make requested boost. I believe Marski posted a few video on his testing procedure, did you find those videos and or threads on the site? Like other have said either something is not connected correctly, or you have massive leak. I would not go WOT (wide open throttle) until this is addressed (at the very least). If you don't already, learn how to lower your engine down 3-4 inches, this may come in handy when dealing with leaks and replacing parts on the top of the engine.

Possibly a bad check valve somewhere, on the drivers side, there is an evacuation tube that is near the turbo (in the wheel well), coming from above, when you pressure test, is air escaping through this tube? If so, its your check valve, coming off the plenum behind the throttle body, on the drivers side. You must lower your engine to change this check vavle, a common failure.

There are some good threads on this, I believe I posted a thread on this site years ago, inquiring / showing how air circulates during a pressure test.

 

Did you have boost leaks before you installed the DVs? Are you sure everything went in correctly and is tight?
It is difficult to help a diagnose a boost leak via forum unless you start searching for it. There are a number of things that can cause one.

Here is what happened to my intake manifold when you lower the engine too low. Which apparently the previous owner did. Car would not hold any pressure during boost leak test

 

yes, I have watched Dejays videos as well as Clint’s. All check valves have been replaced and I did lower the engine to gain additional access.

 

Yes I noticed that I was not getting full boost, before replacing all check and diverter valves.
I sure hope it isn’t a cracked manifold. Will have more time to diagnose this weekend.

 

I did some repair on my plastic intake using a two parts epoxy glue in 2012 and it is still holding... My repair was able to withstand a 28 pound leak check.....