Not your ordinary boost leak test question. Help me out

[kmoore]

Hey guys i got some questions concerning boost leak tests that i did. This might be kind of long so please hear me out and i could use any and all help.
About a week ago i got my uicp's and greddy type rs BOV from dejon. Well, i noticed that dejon gave me too big of a coupler (2 1/2") for my upper intercooler pipes so i called him up and asked if he could ship me the right one (2 1/4"). He said sure and he said he would ship me one right away. Well, i used the 2 1/2" uicp coupler for the time being until the right size one showed up. The 2 1/2" was a little big but i tightened it down really tight and made it work. So i got everything tightened down and did a boost leak test with the big coupler and the test showed that i had a boost leak by my throttle body. On my boost gauge during the test showed that i was pressurizing the system to 12 psi which was what i wanted. Got the leak fixed and took it out for a spin. It pulled really hard and i like both products a lot. Then, about 3 days later i got the right size coupler (2 1/4") from dejon. I put the right size coupler on and took the big coupler off. When i put the new coupler on i took off the pipe connected to the throttle body. I then did a boost leak test with the new coupler on and now i can't pressurize the system at all. I had my dad watch my boost gauge while i was trying to pressurize the system and he said that the needle didn't even move at all. I wanted to still see that the boost gauge was working, so i turned on the car and it IS still working. So it's not my boost gauge. So then, i purposely on bolted my BOV a little bit so that i could see if the pipes were getting pressurized. I did another boost leak test with the BOV un-bolted and air was coming out of the flange. So all the pipes up to my BOV are getting pressurized. I bolted the BOV back down and did another one and i noticed that air is coming out of my MAS (that big black box in between my filter and intake pipe). It is coming out of the smaller box inside of the MAS on the right side. Is air supposed to come out of there when doing a boost leak test? Should i block that off? Why can't i pressurize my entire system? What do you think is going on? Please help me out i could really use it. Thanks in advance and sorry for the long post.

 

[oldman]

Well, when i put my hand by the plug (while testing) i am positive it is coming from there.

Just to be clear on this. You did a test from the turbo inlet with the intake pipe off the turbo inlet but still connected to those three emission hoses and you hear and feel air coming out of the mas through the empty plug on the mas. Is that right?

The other alternative is you implying that you're leaking air out of the fuse box side of the electrical plug which is impossible.

But, should i plug those hoses when i do my test?

Only the BCS, fold and zip-tie the hose between the Tee and the inlet of the BCS. If air is coming out of the breather hose, pressure is probably entering the crankcase via turbo seal which is normal during a static test when testing from the turbo inlet. Move the tester further downstream to make sure the turbo is the only crankcase leak.

 

[kmoore]

Just to be clear on this. You did a test from the turbo inlet with the intake pipe off the turbo inlet but still connected to those three emission hoses and you hear and feel air coming out of the mas through the empty plug on the mas. Is that right?

The other alternative is you implying that you're leaking air out of the fuse box side of the electrical plug which is impossible.


Only the BCS, fold and zip-tie the hose between the Tee and the inlet of the BCS. If air is coming out of the breather hose, pressure is probably entering the crankcase via turbo seal which is normal during a static test when testing from the turbo inlet. Move the tester further downstream to make sure the turbo is the only crankcase leak.

To the first part- Yes i did a test from the turbo inlet and yes i took the intake pipe COMPLETELY OFF THE CAR. Then i let all three emissions hoses hang, not connected to the pipe because the pipe is off the car.

I unplug that plug from the MAS when i do my boost leak test and yes i hear and feel air coming out of that plug. And no i am not implying that i am leaking air out of the fuse box side of the electrical plug, i am saying that that plug is coming from there (from the fuse box) to my MAS.

Also, what do you mean when you say "between the tee" of the hose from the BCS? Thanks for your help with this

 

[oldman]

I unplug that plug from the MAS when i do my boost leak test and yes i hear and feel air coming out of that plug. And no i am not implying that i am leaking air out of the fuse box side of the electrical plug, i am saying that that plug is coming from there (from the fuse box) to my MAS.

This is where I'm confused, didn't you remove the mas and filter with the intake pipe? If the intake pipe is removed during the pressure test, why is the mas still in the car.

Also, what do you mean when you say "between the tee" of the hose from the BCS? Thanks for your help with this

There is a hose from the compressor housing and a hose from the actuator, they're t'ed together by a T connector, the third connector/hose on the T connector runs to the inlet of the BCS, pinch this hose to prevent pressure from reaching the BCS.

 

[kmoore]

This is where I'm confused, didn't you remove the mas and filter with the intake pipe? If the intake pipe is removed during the pressure test, why is the mas still in the car.


There is a hose from the compressor housing and a hose from the actuator, they're t'ed together by a T connector, the third connector/hose on the T connector runs to the inlet of the BCS, pinch this hose to prevent pressure from reaching the BCS.

No i didn't remove the MAS from the car i just removed my filter and intake pipe. Even if i took the MAS out of the car that plug will still be there and still be leaking air. So, either way that plug is still leaking either way. What i want to know is, is this plug causing me to not pressurize the entire system? And SHOULD this plug be leaking?

Also, should i be worried about pinching off this hose and blocking the end of this off? Could i screw anything up if i do it wrong? Thanks again

 

[S_Ranger]

Have you done anything about this problem yet. While your waiting for a reply go check your tb gasket, ziptie your vacuum lines, etc. Who knows, something might spark in your mind and you'll find the solution yourself. GIving you more knowledge and what not.

 

[kmoore]

Yeah, i have checked everything. Whats weird though is before i put this new coupler (the correct fitting one) on and had the old one on, i did a boost leak test on that and it work fine. That is with out pinching off the BCS hose and zip tieing it. When i did the boost leak test with the old coupler on i did not notice air coming out of that plug. So i have no idea what is up? Also, i don't know if this matters but when i installed my uicp and my greddy type rs BOV and i started it up, i noticed that my BOV was whistiling when i would give it a little gas. Just a little though. Any help with pinching off this hose thing would be appreciated also.

 

[skinnykenny84]

What is this "plug" thing? The only thing I consider a plug on the maf is the actual wiring harness. Obviously thats not leaking if you got the entire intake off the car. I think you are talking about the breather hose that runs from the left side of the valve cover to the intake pipe. Am I right? Now it will leak during a boost leak test..... Do you have a camera you can go take a pic with and point out to us what your talking about?

Also, if you had no problem untill you took your upper intercooler pipe off (aka throttle body elbow) and now you do, then that would be the first place to investigate. Is it possible that one of the gaskets fell down while reinstalling the pipe to the throttle body? The reason I ask is those bolts hold everything together (uicp, t.b.>intake) and if your not carefull you can loose one of the gaskets while reconnecting.

 

[kmoore]

What is this "plug" thing? The only thing I consider a plug on the maf is the actual wiring harness. Obviously thats not leaking if you got the entire intake off the car. I think you are talking about the breather hose that runs from the left side of the valve cover to the intake pipe. Am I right? Now it will leak during a boost leak test..... Do you have a camera you can go take a pic with and point out to us what your talking about?

Also, if you had no problem untill you took your upper intercooler pipe off (aka throttle body elbow) and now you do, then that would be the first place to investigate. Is it possible that one of the gaskets fell down while reinstalling the pipe to the throttle body? The reason I ask is those bolts hold everything together (uicp, t.b.>intake) and if your not carefull you can loose one of the gaskets while reconnecting.

No, its not that hose it is the plug on the MAS. If you are looking at your MAS from the front there is a plug at the top of the MAS with a bunch of wires coming out of it to what looks the fuse box. Here i'll try to get a pic...http://www.dsmtuners.com/gallery/showimage.php?i=1284&original=1&c=searchresults&searchid=13153 I hope it works. It's from the gallery not actually my car. See the plug on top connected to the MAS (the black box thing) When i unplug that from the MAS it leaks air when i do a test. I hope this clears things up.

 

[skinnykenny84]

Yes, we are talking about the same thing. Anyway, how is it leaking there if you have the intake off the car?? ! I dont get it. You said you had your boost leak tester directly on the turbo inlet, if thats the case then there is no way you have the intake hooked up and there is no way air can be leaking from the maf or anything on the intake since its not connected., Right?

 

[danny_l_2005]

As i've been reading this post it got me kind of confused. The plug your talking about its the connector of the MAS, which is electrical and by no means will it ever leak boost becuase its not even a boost source. Maybe your leaking boost through the bov and thinking its from the MAS connector. I would say check your bov, and do another boost leak test with the T/B vacuum lines cap and BCS capped also. And we'll see from there

 

[kmoore]

First of all, i'm a little confused you are saying "MAF" and i'm saying "MAS". I'm guessing it's the same thing that we're talking about. Anyway, when i do this test i take off everything. I take off the intake pipe, the air filter, and the MAS or "MAF" (the black box thing). But, to take off that black box thing you have to unplug the electrical plug to get it off the car. But, the plug is still hanging there because it's connected to inside of the fuse box. Well, like i said, that plug leaks air out of the end of it (the end where it would connect inside of the MAS or "MAF"). I think this is why i can't pressurize the system. I mean isn't this the way you guys do boost leak tests? Don't you take off MAS and if you do, don't you leave that plug alone and does it leak for you?

 

[oldman]

don't you leave that plug alone and does it leak for you?

Did you spray down the fuse box with soapy water and check for bubbles? joking of course. The answer is "no", this is why everyone is so confused, how can an electrical plug leak air? I even tried to confirm this with you on page one.

Just to be clear on this. You did a test from the turbo inlet with the intake pipe off the turbo inlet but still connected to those three emission hoses and you hear and feel air coming out of the mas through the empty plug on the mas. Is that right?

The other alternative is you implying that you're leaking air out of the fuse box side of the electrical plug which is impossible.

Your answer to my question was.

And no i am not implying that i am leaking air out of the fuse box side of the electrical plug, i am saying that that plug is coming from there (from the fuse box) to my MAS.

 

[kmoore]

Yeah, i know i was like WTF when i felt and heard air coming out of that plug. That is why i am asking because i just don't know what's up. But, i know what i know and i just don't know why that plug is leaking air. I am going to do another test and i will get back to you guys. So, let me clear this up, when i am pinching off the hose and capping it which hose do i pinch off? Do i pinch off the hose between the turbo and the BCS or do i pinch off the hose between the BCS and the intake pipe? If i pinch off the hose between the BCS and the turbo do i actually take off that hose or can i just leave it connected to the BCS. Thanks i going to do the test right now

 

[kenamond]

Couple of questions about your setup:

When you first installed your UICP, did you have to remove the throttle body (TB) elbow (does the UICP bolt straight up to your TB)? The stock setup has a flexible hose that clamps to the TB elbow. My UICP replaces the TB elbow. Someone already mentioned this, but I want to make sure you understand.

If your UICP bolts straight to your TB, then the 4 bolts that hold it to the TB also hold the TB to the intake manifold (IM). So when you got your new coupler from Dejon, if you unbolted the UICP from the TB, you probably reintroduced boost leaks in one or both of the TB gaskets (there's one gasket on either side of the TB).

Also, is your BOV vaccuum line connected to your intake manifold? If you disconnected that when you changed the coupler and forgot to reinstall it, the BOV could be leaking.

Finally, there is no way that you have boost leaks in your MAS plug. I agree with the other guy who suggested that your BOV is leaking, and since it is close to that area of the car, you're mistaking that leak for a leak in the MAS plug.

 

[skinnykenny84]

Exactly, there is no way on earth that electrical wiring is gonna leak air! Do another test, maybe this time have a friend to help you so you can check more than one area at a time, watch the boost gauge etc..

Mix up some soapy water in a spray bottle and spray suspicious areas and look for bubbles.

Report back private!

 

[93ESTalon]

The plug will just hang there chilling in the engine bay. It's an electrical plug and there is not any air leaking out of it during the test. It's impossible. You're leak is probably in your UICP or somewhere close by the plug.

 

[kmoore]

Hey, guys. First off, i just want to apologize for not getting back to you guys sooner.
But, i had to build a new boost leak tester because my old one crapped out on me. Also, with school and everything i am kind of pressed for time.

Well, i finally did another boost leak test and i realized that the air that i am feeling is coming out of the BOV. The air is escaping around where it dumps back into the intake track. I bought the re-circulating piece for my greddy type-rs. When, i pressurize the system i feel air coming out of the opening of the BOV. So i tightened down the BOV to the "harder" setting and air was still escaping when i pumped air into the system. Should i keep tighening down the BOV? Why is it escaping through the opening? Just FYI it is not escaping through the gasket, just where the BOV would connect to that dump tube on your intake pipe. Thanks a lot and any help would be appreciated.

 

[1stGenRocks]

do you have a mbc or boost guage or anything tapped into the small line to the bov? if the bov is partially opening that means that it isnt getting as much pressure on the top as the bottom. anything leaking on the bov line will cause this. also make sure your line isnt cracked at either end

 

[kmoore]

Well, i just took off the BOV and it looks like it doesn't want to stay closed!!! What i mean is when i look at the bottom part of the BOV i see that it doesn't want to seal properly. It doesn't want to stay closed. What should i do? I bought it from dejon tool. Is it defective?

 

[kmoore]

I also noticed, that on the bottom part of the BOV on the RS there is what looks like a slit or groove for a flat-head screw driver to fit in to. Can this bottom plate looking thing be adjusted so that it closes correctly? Thanks

 

[jabinya]

When you say MAS do you mean MAP?

Turning the BOV plate on the bottom doesnt affect the BOV, it just turns it. The only way to adjust is to turn the bolt on top of the BOV. This increases or decreases spring pressure. which allows you to hold more or less boost.

Do you have the lower nipple on the BOV connected? That would cause the BOV not to seal properly during a boost leak test.

Here is a FAQ on the Greddy BOV operations; <a href="http://www.stealth316.com/2-greddy-bov-anatomy.htm">Greddy BOV Anatomy</a>

Perhaps you are leaking at the BOV flange or the rubber seal that surrounds the valve plate.

I've taken mine apart before just to see how it works and found that it is repairable if needed.