boost leak testing questions
 

I have built a tool, with a gauge on it to see how much pressure is in the system, My car will hit 20.8 psi on a good day, but lately it has gone down to 18psi. Sol i started fixing boost leaks, Now I have gotten back up to 20psi, but i feel as if the boost is falling off too fast. my vacuum is steady at 20hg during Idle. before i started fixing things, the car when first cranked would only have 10hg vacuum until it warmed up and then it would go to 18-19 hg

GENERAL BOOST LEAK QUESTION

Should the system hold the air pressure for an extended time? (my system will hold some pressure but it wont hold 10psi steady.) Or is it acceptable that some small amount of air will leak out. If so how much is too much.

I have been beating my brains in trying to find and fix all the leaks on my 1.8t that i found after chipping it. So far i fix 3 leaks. I still have a honk noise on the back of the motor that i have not yet to locate. The plastic y piece at the top of the motor in the back has a small leak, i couldnt see too much pressure escaping it, but i am going to pull the part and inspect it. maybe replace.

Would a cracked crank case breather hose cause a loss of boost?

RE: boost leak testing questions
 

keep in mind even a small leak will open up when under 20lbs of pressure. thats what the honking noise is most likely, a small leak that you cant see but opens up under pressure.

it also wont hold pressure, it will need to have pressure supplied to it much like the turbo does when its running. I used a pressure regulator to cap it at 20lbs otherwise you will blow something depending how much pressure your air compressor can make

RE: boost leak testing questions
 

I am using a portable tire pump plugs in to cig lighter, it sucks but it is what I got, I can charge my system up to 10 psi, but as soon as I remove the compressor it leaks donw in about 10 -15 seconds. and it the leak is bad enough to where i can get it over 10 psi with the compressor. i need somthign that can put out more air.

I put a gauge on the tool for the as to not put to much psi into it and to watch the fall off. I feel like I am taking the cars blood pressure

RE: boost leak testing questions
 

Ok , well i fixed another leak, a suuper tiny one, it took me removing a plastic y piece and plastic welding the seal area,
well now the pressure will get a little higher but i still havent been able to get more then 10 psi with my shotty portable pump. but i couldnt hear anymore hisses, just a gurgle in the oil pan, which i would suspect is normal. where does that air go after gurgling through the oil"?

I am going to put everything back together and go for a spin.

RE: boost leak testing questions
 

mine made that gurgling noise too, i was sure to block off the pcv valve but i thought i was messing something up... where are you hooking into the system? i built a deal that i clamped onto the TIP and it had a air fitting on the end, i then hooked on my pressure regulator then into compressor.. stopped the regulator at 20psi and let it charge (.002 seconds) but i have a big aircompressor... you need to make that piece like on www.a4mods.comthen find a real air compressor to test it

RE: boost leak testing questions
 

I made one similar to the a4mods.com. I just measured the tip opening and made a tool with some pvc, shit looks almost identical to the a4mods. I blocked off the pcv valve hole.
Well to update you, I have fixed all of the leaks, found a hose with a clamp that had been put on crooked. put a new clamp on, and boost is holding.
I bought a compressor from sears, used it and returned it 2 hours later.
but yeah thanks for the help