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Boost Leak Test assistance

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LASER4G63T

15+ Year Contributor
91
0
Apr 4, 2005
Fort Worth, Texas
Hey guys

I'm in the Western Massachusetts area right now (Westfield to be exact). I either have a very big boost leak or am doing something wrong in the test.

Is there somebody around the area who could help me run a BLT who knows what they're doing? Thanks.

I have a 14b.
:laser:
 
That link is great. Where is your boost leak at that's "pretty big?"
 
Instead of the Schrader valve in the link, I switched to a male compressor fitting that normally screws into an air tool with a small ball valve to shut of the air supply to test the leak down time.

That schrader valve pissed me off b/c you have to manually hold the damn hose on and it is hard to do a good BLT b/c the air bleeds off and some small leaks don't appear until 25-30 psi and it never held that psi long enough.

With the compressor fitting you just hook up the compressor to it and it feeds constant air to keep the system charged which makes it easier to find small boost leaks.

Here is a pic. Probably cost me $30 total and I got the ball valve from Lowes for $8.
 

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Thanks. The problem is I don't know where this leak is or even if it exists. I just can't hold any pressure..which is odd because the car runs great. I was just doing this as a maintenance test and can't seem to hold any pressure. I'll try sectioning the intake off smaller like in the article.
 
What are you using as your air pressure source? I tried bike pumps and hand air pumps and couldn't produce pressure quick enough to find the leak before it lost pressure. Bought(and returned) an air tank, filled it up at a gas station, hooked it up and found the leak within minutes.
 
Get a spray bottle with some soapy water.

Thats the only way I found my leak when it bled off too quick to know.

Spray it all over suspicious areas then pressurize the system and take a walk around
 
Too bad you're in East Bum F*** or I'd come over and help. You should hear the "hissing" of escaping air if you have a boost leak. Absolutely use soapy water. Also don't forget to take off the valve cover oil cap, as air will generally escape out of there anyways. And if you have any hard intercooler piping, put the boost leak tester on that instead. Repeatedly applying pressure using the compressor-side housing puts unnecessary stress on the rest of the turbo (including the bearings).

You may also consider looking through this thread for more info and pictures.
http://www.dsmtuners.com/forums/new...se-troubleshoot-boost-leak-tester-merged.html

And here is another helpful thread where I posted pictures of how a pressure gauge can be installed (especially if you have an MBC).
http://www.dsmtuners.com/forums/newbie-forum/241831-no-boost-leak.html
 
Thanks for all the great advice! I'm gonna try it again on Saturday. It shouldn't be this hard! LOL
 
I've read through many threads about this boost leak test...I must be retarded because...I bought the BoostPro tester w/ gauge, indexed the motor to 30* ATDC as recommended in another thread (for minimum valve overlap), and am using a portable 7gallon tank filled to 50 psi.

I go to pressurize the system, and while no measured pressure is present, I can hear air going into it. I managed to find a small leak at the EGR block-off plate, which I fixed, but that can't account for no readable pressure at the gauge.

EDIT- Found another leak at inner TB gasket, but still...WTF
 
Can you hear air escaping anywhere? Take a spray bottle and start spraying soapy water on all piping, joints, intercooler, intake manifold, injector base, vacuum lines, bov, basically everywhere that sees boost. I had a bad one not long ago and found that the seam of the piping on my upper ic pipe had a crack about 3 inches long. You couldn't see it, but as soon as I put 25lbs to it you could damn sure feel and hear it.
 
yeah I've done the soap and water, opened the throttle and kept it closed, doesn't matter. I know I have a leak at my TB gasket, but it can't all be escaping from there. I'm really running out of ideas and time as I was supposed to be done a month ago :banghead:
 
i'll check compression in the AM, but I'm betting it's good as this is a relatively fresh motor with about 600 miles on new internals
 
Ok, well compression is about 180. I actually got the thing to idle smoother now, so the couple boost/vac leaks i fixed probably helped some. There is still a loud hiss coming from the TB area that I can't pinpoint. I put a thin bead of rtv on the gaskets and sealed them up, but by the look of the imprint of the mating flanges, they were sealing pretty good as is. So what do you guys think I should do next?
 
There is still a loud hiss coming from the TB area that I can't pinpoint. I put a thin bead of rtv on the gaskets and sealed them up, but by the look of the imprint of the mating flanges, they were sealing pretty good as is. So what do you guys think I should do next?

Throttle Body O-Ring
 
Yeah that looks like a lot of fun. Thanks for the link though.

Yeah I was kinda scared to do it at first too, but once you start taking things apart you'll realize how simple it actually is, trust me, the link makes it looks hard, it's not, not at all.
 
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