Boost Leak from Boost Controller?

[Spoolin98]

Hey guys I need some help with a boost leak. I did a leak test and im losing air from a hole in a nut on my boost controller. I dont think this should be this way, any advice or comments on why this is or what i should do? Should i just JBweld the hole shut? Heres a link to the picture of the hole that the air is leaking from, its a fairly large leak that will not allow the car to hold pressure. Thanks in advance.

http://www.allaboutimports.com/boostcontroller.html

 

[oldman]

Step one in leak testing is to disconnect or turn the mbc all the way up. The hole is suppose to be there to bleed off pressure, without it, pressure gets trapped when the ball in the mbc returns to its original position after you let off from boosting resulting in the wastegate staying open.

 

[Spoolin98]

Step one in leak testing is to disconnect or turn the mbc all the way up. The hole is suppose to be there to bleed off pressure, without it, pressure gets trapped when the ball in the mbc returns to its original position after you let off from boosting resulting in the wastegate staying open.

Your the man, thanks for help!

 

[oldman]

You're welcome.

 

[Spoolin98]

You're welcome.

Hey oldman do you think you could help me with a few of my other problems? MY brother bought a 1g tsi awd, and it has been nothing but problems. He has had it for about two months and the turbo was already replaced and I just got done pulling the motor to fix broken halfshaft bolts. Since I put the motor back in, I ran into numerous problems, most of them I have fixed, but I still have a few. MY problems are:
#1 The cel is on at idle, and turns off when on the throttle, then back on at idle.
#2 At around 3K to 4K the car studders, but still hits full boost (12psi) to redline. It never
stutters at WOT.
I have searched and found that most people say plugs and wires. I will check that
tom.
#3 When I do a boost leak test, air sounds like it is leaking past the throttle shaft, I cant feel
air leaking anywhere, I can just hear it. I am assuming its the throttle body seals, Is this
right? Could this be the cause of the stuttering, I dont think so, but its one more thing to
rule out.
Thanks in advance, any help is appreciated guys.
Sorry for writing a book.

 

[oldman]

1. http://www.vfaq.com/mods/wayback/BradBauer/electrical/code.html

2. NGK BPR6ES at .028", changing the wires is a good idea. Also, just because you are holding 12psi to red line doesn't mean there are no leaks, it just means the turbo is working harder to maintain the pressure and make up for the lost air. Hitting fuel cut at 16 psi is a clear indication of boost leaks.

3. You are assuming the shaft seal leaks are the only once, you have much to learn about leak testing. The final goal is 20psi on the real bost gauge and allow no less than 30 seconds before it bleeds down to zero. Here are some tips for you on leak testing besides disconnecting the mbc.


1. Move your tester to the TB elbow to focus on smaller areas at a time, work your way back to the turbo inlet once the conditions are satisfied.

2. Listen for hissing under the oil cap as well as the tailpipe.

3. Spay soapy water on injector bottom seals, intake manifold gasket, EGR valve, TB gaskets, shaft seals and BISS screw, leaks will reveal themselves as bubbles. Remember, 20psi for 30 seconds. If you can't find the shaft seals, pm me.

Good luck.

 

[Spoolin98]

Well Bruce I appreciate your help, unfortunately I am back at school now and did not get a chance to get my brothers car running properly. I checked the gap on the plugs, they were anywhere from .030 to .040, so i gapped them to .026-.028. Took the car for a ride and it is still stuttering. I didn't check the cel code yet, I am waiting on my brother to order a pocketlogger cable so I can hook up my palm. Thanks for all your help, esp. the tips on leak testing. Ill keep you posted next time I'm home.

 

[power=dsm]

1. http://www.vfaq.com/mods/wayback/BradBauer/electrical/code.html

2. NGK BPR6ES at .028", changing the wires is a good idea. Also, just because you are holding 12psi to red line doesn't mean there are no leaks, it just means the turbo is working harder to maintain the pressure and make up for the lost air. Hitting fuel cut at 16 psi is a clear indication of boost leaks.

3. You are assuming the shaft seal leaks are the only once, you have much to learn about leak testing. The final goal is 20psi on the real bost gauge and allow no less than 30 seconds before it bleeds down to zero. Here are some tips for you on leak testing besides disconnecting the mbc.


1. Move your tester to the TB elbow to focus on smaller areas at a time, work your way back to the turbo inlet once the conditions are satisfied.

2. Listen for hissing under the oil cap as well as the tailpipe.

3. Spay soapy water on injector bottom seals, intake manifold gasket, EGR valve, TB gaskets, shaft seals and BISS screw, leaks will reveal themselves as bubbles. Remember, 20psi for 30 seconds. If you can't find the shaft seals, pm me.

Good luck.

hey Bruce i'm on the forum alot and everyone always seems to ask you about boost leak test. I was just wondering since you always help out other dsmers have you written up a vaq on boost leak testing ?

 

[oldman]

hey Bruce i'm on the forum alot and everyone always seems to ask you about boost leak test. I was just wondering since you always help out other dsmers have you written up a vaq on boost leak testing ?

I have been asked that many times and my answer is still the same, "I hate homework"

 

[oldman]

Well Bruce I appreciate your help, unfortunately I am back at school now and did not get a chance to get my brothers car running properly. I checked the gap on the plugs, they were anywhere from .030 to .040, so i gapped them to .026-.028. Took the car for a ride and it is still stuttering. I didn't check the cel code yet, I am waiting on my brother to order a pocketlogger cable so I can hook up my palm. Thanks for all your help, esp. the tips on leak testing. Ill keep you posted next time I'm home.

You're welcome and good luck.