How did i do this BLT wrong?

[tay97gst]

Well i made myself a boost leak tester this weekend and attached it to the turbo inlet. So the whole intake system was gone. I compressed the system to 15 psi which read on my boost gauge. At this point i used the soapy water and sprayed it on all vacuum hosing and things boost related. Now, my car isn't in the best condition because it was neglected before i bought it so honestly i was expecting a lot of bubbles but i honestly didnt see any. The only thing i heard was air escaping somewhere behind the throttle body it sounded like.I really dont think this is my only boost leak so did i do something wrong? was anything supposed to be plugged or something?

 

[92AWDHX40]

Could be the throttle body or egr valve, keep spraying the areas youll find it when you see bubbles.

 

[Tyeler18]

How quickly did pressure bleed off? It definitely could be your only leak and sounds like a tb gasket is leaking.

 

[Junfan]

Did you follow the VFAQ and make sure to be 30* atdc? I have made that mistake before. TB gasket, FIAV and shaft seals can be problems in the area you described.

 

[crash89]

It may not be your only boost leak.. Its most likely your largest one.. Once you fix that one another will emerge.. The air is going to escape through the path of least resistance so to speak. Things where you are describing could possibly be a TB gasket, EGR valve, vacuum lines, intake gasket.. There is a bunch of stuff going on in that are.

Its easier if you have a friend with you to charge the system after the air bleeds out. Also easier to tap in a pressure gauge on the tester itself. Take your time man..

 

[And_44]

All those area's are there and common. But I'd add fuel injector O-rings. My leaky ones sounds as if they were coming from behind.

 

[tay97gst]

Hmm.. now that i think about it, after i remove the compressor fitting from the BLT should theoretically stay pressurized until it all leaks out correct? I think mine depressurized right after the compressor was removed. Does this mean i have a really big leak? And if i had a really big leak could all the compressed air be escaping from that one area and not really putting pressure to other parts of the system causing no bubbles cause its all leaking from there? Sorry if that doesnt make sense haha

 

[97gsxerrr]

I would pressurize the system a few more than 15psi. Say 20psi. That way if your system holds 20psi then it will for surely hold 15psi.

 

[jrohner]

throttle seals are probably leaking, they usually do.

 

[jpmxrider489]

Throttle body is a common place to leak. That's why I got mine rebuilt.

 

[bstaley]

I just experienced this 2 days ago, my leaks were both base throttle body and throttle body elbow gaskets, also my biss o ring was leaking. I ordered the two gaskets from ExtremePSI that was the best deal I found.

 

[1990AWD]

Hmm.. now that i think about it, after i remove the compressor fitting from the BLT should theoretically stay pressurized until it all leaks out correct? I think mine depressurized right after the compressor was removed. Does this mean i have a really big leak? And if i had a really big leak could all the compressed air be escaping from that one area and not really putting pressure to other parts of the system causing no bubbles cause its all leaking from there? Sorry if that doesnt make sense haha

What kind of fitting are you talking about? Its easiest to use either a tire valve stem or some kind of valve on the BLT so you can actually pressurize it up and be able to walk around the engine bay spraying soapy water and looking and listening for leaks.

 

[Tyeler18]

Hmm.. now that i think about it, after i remove the compressor fitting from the BLT should theoretically stay pressurized until it all leaks out correct? I think mine depressurized right after the compressor was removed. Does this mean i have a really big leak? And if i had a really big leak could all the compressed air be escaping from that one area and not really putting pressure to other parts of the system causing no bubbles cause its all leaking from there? Sorry if that doesnt make sense haha

Yes that makes sense, and yes that could definitely be the problem. Majority of the air will leak from the easiest place (aka your biggest leak). A solid system in my eyes (and most on here) would be to hold pressure for around 2 minutes and slowly bleed off. Make sure you're testing ABOVE what you're running for boost just to insure that you won't be leaking at your desired PSI. Chasing boost leaks sucks (I'm doing it right now) but it's well worth it having a solid system.

 

[tay97gst]

Yes that makes sense, and yes that could definitely be the problem. Majority of the air will leak from the easiest place (aka your biggest leak). A solid system in my eyes (and most on here) would be to hold pressure for around 2 minutes and slowly bleed off. Make sure you're testing ABOVE what you're running for boost just to insure that you won't be leaking at your desired PSI. Chasing boost leaks sucks (I'm doing it right now) but it's well worth it having a solid system.

Alright thanks, thats what i figured. Ill try and get my hand around there to try and pinpoint the leak, this is gonna be a pain x)

 

[1990AWD]

Soapy water is your friend.

 

[4g63t]

Hmm.. now that i think about it, after i remove the compressor fitting from the BLT should theoretically stay pressurized until it all leaks out correct? No I think mine depressurized right after the compressor was removed. Does this mean i have a really big leak? No And if i had a really big leak could all the compressed air be escaping from that one area and not really putting pressure to other parts of the system causing no bubbles cause its all leaking from there? Sorry if that doesnt make sense haha

You’re most likely blowing air past the valves/pcv system. Air will bleed off.