no boost?

i'm looking to buy this guys tsi awd, and he has a t28 in it, and can't run any boost.... i was wondering if there was anything i could tell him to check.... here's what he's said so far.

I can't boost above 2 psi...

And I dont think its leaking because its not running rich (It wont fall on its face like it should)...

I taped off the bov thinking that was it, but its not. And I know the turbo is boosting because the BOV blows off alot of air when it opens.

Anyone have any suggustions?

Vaccum is -15psi at idle
BOV - Greddy Type-S
Turbo - t28

so the only thing with it might be the wastegate itself.. but i think its ok, because when the car was idleing i could open and close the wastegate and it ran different when i opened it.. which makes me think its closing right.

thanks guys, any thoughts?

i was under the impression that the wastegate spring was supposed to be really tight and that you couldnt usually open it by hand with the turbo on the car.

he says it was off the car when he did it; when its on the car he cant move it......

is the exhaust manifold to head gasket and the exhaust manifold to turbo gasket good?

edit>> you said in the firast post that you could move the wastegate with the engine running and it changed how the car ran then later you said that you could only move the wastegate with the turbo off the car. which is it?

yeah, he's pretty sure they are..... :(

...well he thinks they're ok. he says it doesnt sound like they're leaking.... also, the turbo seems good, no shaft play or anything....

interesting... did you see what i edited in about the wastegate? you said in the first post that you could move the wastegate with the engine running and it changed how the car ran then later you said that you could only move the wastegate with the turbo off the car. which is it?

the t28 in internally gated, so when he said he could open and close the wastegate, he meant he could move the lever open and closed, withought the actuator on there. when the actuator is on the car, the lever is pulled all the way to the left, in the closed position

does that make any sense? sorry if im not

yea it makes sense

so do you have anything else that he might check?

i dont know. does it sound like its blowing off constantly? im not sure how soft a greddy types can go but make sure its hard and check the gasket on the bov flange. maybe try replacing the exhaust gaskets and the bov gasket. also make sure all the ic hoses are clamped tight and make the leak tester on vfaq.com

Has he verified the boost guage works? I know it sounds too obvious, but its usually the most obvious thing that poeple will overlook. The only way it can acutally get only 2 psi if there are no major boost leaks is the WG is opening prematurely or not sealing right when it is closed. It is possible for the flapper to be misaligned, but it would have to be way off to get no boost. That usually just gives tons of lag (like 6k rpm on a 14b).

maybe he installed the boosst controler wrong casuing the WG to open all the time....

boost controller can only raise the max boost it cant do anything to make the boost lower then normal.

so kevin how would i know if that was the case?

The misalignment? You can tell from the outside of the turbo if you know what you are looking at. Not something I can easily describe though. The flapper arm should be about 1/4 inch from the turbine housing. Gravity and heat will make it slide out further. Usually only happens on old turbos though, so I'm not sure how likely this is. But if its out like 1/2" or more, its misaligned. I woudl aski him if he has verified that the boost guage is accurate. Shit, could be a tear in the vac line, or a crack if its hard nylon line. Not at all uncommon. Of course thats bad becuase people will keep cranking up the MBC, and the guage doesnt reflect how much boost you are really running ;)

I guess what we need to know is he jsut going by the guage? Does it feel like its only 2 psi (basically NT)? Does it lag like hell? Etc.

he also has a 2g gst, and says he knows what double-digit boost feels like, and this sure as hell aint it. he says it just drives like a n/t. i guess i shouldnt be that worried about it, because its just something i could do myself when i got it, right? i mean, chances are its the induction system and not the engine itself, so it shouldnt be too too expensive..... right?

That would be my assumption. If compression checks out odds are it's a relatively easy fix, maybe a new turbo at the worst.

thanks, i'll update you if we make any headway :)