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Discussion Starter #1
i seem to have a leak in the turbo area.
when driving i can get the turbo to boost to about 10 lbs but during that time i dont seem to have the power that i should. and i hear a lot of air escaping from somewhere while its boosted.

does anyone have an idea where this air is escaping from?







thanks
 

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Well, there could be an exhaust leak, or the intercooler could be leaking, either at the intercooler itself or one of the hoses to or from it.
 

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Anywhere in the induction system
BOV
PCV and related hoses
vacuum lines
TB base gasket
 

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Discussion Starter #4
well ok i made up a little pressure testing system and pumped air into the intake.
i found 3 places where air leaked 2 of them were negligible but one was a bit more airflow.

one spot was on an unusual cap that came off of some small cylinder that was on the pass side and it had 30ohm on the top (small leak)
the next spot was a small amount of air coming out of the blowout valve? (on the engine side of the air filter)

but the biggest flow was coming somewhere from between the turbo and the waste-gate. the 2 vacuum lines going to the waste-gate were fine, the air seemed to be coming from between where the gate mates with the turbo itself. is this a plausible location?

thanks for help so far
 

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Discussion Starter #5
heres some pics

the leak at the 30 ohm cylinder

i seem to have trouble putting more pics on
 

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but the biggest flow was coming somewhere from between the turbo and the waste-gate. the air seemed to be coming from between where the gate mates with the turbo itself. is this a plausible location?
That sounds like an open exhaust valve, which would be normal. The small cylinder would be the wastegate control solenoid, also normal.
 

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Discussion Starter #7
hmm if those are both normal then it just might be an exhaust leak. but personally i dont understand how a leak on the exhaust side can reduce power
 

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Huh?
 

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Discussion Starter #9
umm?!?
are you implying exhaust has nothing to do with this
 

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I'm asking why you think it does...I don't follow your thinking.
 

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hmm if those are both normal then it just might be an exhaust leak. but personally i dont understand how a leak on the exhaust side can reduce power
Seriously? You don't see how an exhaust leak can affect turbo power (turbo being driven by exhaust pressure)?
 

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Discussion Starter #12
Sorry bob. I understand that the exhaust is what makes the turbo spin up.

But the turbo is spinning and producing boost but it doesnt seem like the boosted air is getting intothe engine.

So im getting about 10lbs but not the horsepower that comes with it.

So thats why i think the the exhaust isnt the factor. But i can be wrong. Which is why im here asking

I guess i diddnt word my earlier reply too well
 

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Discussion Starter #14
As far as im aware i am. But i dont know how to identify the vnt components to verify

edit: ok ive read up on vnt and standard turbos. regular turbos have just a wastegate that is controlled by pressure but the vnt is controlled by vacuum, and i noticed that my wastegate has the 2 vacuum lines coming out of it
 

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Discussion Starter #15
ok i believe i narrowed this down to the blowout valve. does anyone know how to get it off the back of the airbox. and where can i get a replacement. the local chain stores dont carry them. i also need that elbow that goes from the airbox to the turbo intake
 

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Bypass it all together. If you're leaking around the BOV in the air box, simply block all the hoses to the BOV to prevent both vacuum and boost from getting to it. If this solves your problem you'll need to either leave it that way or get an aftermarket BOV which is then put in line with the boost to the throttle body.
 

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the blowout valve. does anyone know how to get it off the back of the airbox.
Assuming you're talking about a '90-'93 airbox, I don't think you can remove it, one side is molded right into the box and the other side is glued down.
 
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