Anybody have any advice as to how to track down a boost leak? First I'll give you the symptoms and then what I've done to troubleshoot..

Symptoms:
- Boost is set to 15psi, I'm only seeing 5psi at redline!

- Turbo is more noisy now, ie. when I accelerate the "whoosh" from under the hood is alot more pronounced than it used to be.

- BOV sounds different now. It's a Tial, and used to have that fluttery/gobbling turkey sound, now it's just "psshhhh".

Troubleshooting:
- I bypassed the AEM boost control solenoid and did some test runs on wastegate spring pressure (~7.5psi) yet I still only got 5psi.

- Took apart the Tial wastegate and did a visual inspection, it seemed ok though I dont know how much you can rely on a visual with these things

- Took apart the Tial BOV, and like the wastegate, it seemed ok from a visual inspection, (no holes in the diaphragm and whatnot) but I'm wondering if something could still be wrong with it

- Inspected all the IC piping, like the wastegate and bov, there was nothing noticeably wrong with any of the piping or fittings, but again, could there still be something wrong that the naked eye won't find?

I really don't know where to go next with this, and it really sucks only boosting 5psi on a built engine. It's getting frustrating. If anybody has any advice as to any more troubleshooting I can do, I'd hugely appreciate it because I'm kind of at the end of my rope with this. There's got to be some efficient way of finding where the problem lies aside from taking everything apart, I'm hoping.

 

find someone with a smoker.

 

smoker? what is that?

 

You can cap both ends of the charge piping, but put a fitting in one of the caps so you can put pressurized air in the piping. A low pressure regulator will do wonders at making letting you pressurize the pipes. 5-15PSI would be plenty.

Mix up some liquid soap and water in a spray bottle and spray all the piping and intercooler. Look for bubbles and you've found the leak.

Since the turbo is making more noise, I'd be more suspect of some damage to the compressor wheel and that's what is causing your low boost.

 

 

Depending on where the leak is, simply putting your head in the engine bay while its running might find you the leak, probably a small hissing noise.

 

If you take the hose off you should be able to cap the end of the snail with your hand and "feel" whether or not your pushing 15psi (should really force your hand away... like opening a valve on a bike tire).

If it's not even making 15psi, then you don't have to looking for a "leak."

If making 15psi, then look for leaks in the soap bubble / hissing / smoker ways previously described.

 

Thanks alot for the help guys, I really appreciate it. SlowS2K, it's interesting that you mention the compressor wheel, because I was also wondering if there could be something wrong with the turbo itself. Because I could see losing a few pounds of boost due to a leak, but to lose 10 full pounds just seems crazy. It seems like that would have to be a HUGE leak, to the point where it would be something that would be immediately noticeable just from looking under the hood, like a huge hole in the IC piping or a fitting that lost its clamp. Anyway thanks again guys, now I have a few more directions I can go to continue troubleshooting this.

 

my car's not holding boost now after i had the intercooler moved up a couple inches (was hanging below the bumper before relocating on 6/10)

the kid i had move the intercooler stripped 2 good clamps that I had, so I got a worm clamp from lowe's while waiting for him to get me another good clamp

the worm clamp blew off the first time i hit boost (later that day on 6/10)

so drove around not making much boost, and picked up the replacement clamp and put it on while on the way to a photoshoot/videoshoot (on 6/11)

tried to boost, and it seemed to hold it for a second, then it sounded like all the air gushed out, or a coupler popped. the one from turbo to intercooler has been the one causing me problems so far, but it looks fine, i wonder if that kid scratched/poked a hole in one of the other couplers....

hopefully its just some loose clamps, i think i'm only getting 1 psi, but i'm still trying to figure out how to configure the TV2 to show psi

oil was also changed at the same time intercooler was moved up

 

i just put my greddy kit on and at tuning shop he ran 32 psi into the kit and i was still only making one psi. we figured out it can be something as little as the MBC or a gasket or just a small vacume line. i just fixed the last one today it was leaking around the secondary air sensor is what i think its called