can hear turbine spin, but no boost at all

[foreverinvayne]

Alright, I have a 90 tsi with the stock 14b at just over 140,000 miles.

THe other day my dad was driving it around town and he said that the spoolup actually kinda scared him cuz he was expecting it and let off hard, then in second gear it had NO spool at all. It didn't even go beyond 0 vacuum. I drove the car and sure enough it didn't go beyond 0 vacuum and it was the slowest thing i've ever driven obviously.

I thought at first that maybe the wastegate actuator arm had come off, but woudln't that cause it to boost too much? or no? I'm not sure about that, but even so, the arm was still attached. No vacuum hoses disconnected and the arm and the actuator that moves still moves just like the wastegate was still working properly.

Also, I know i don't have a big enough exhaust leak anywhere to cause this. And then after i checked all this i still had to drive the car to work and on my way home i was driving through the neighborhood (where there are a bunch of close houses and trees so you can really hear the echo of a turbo) and i could still hear the slight whine of a turbo wanting to spin, but not being able to spool up any boost. This all makes me think the turbo is not actually blown.

So here's my real question. Is it possible for a leak in the intercooler piping or blow off valve to cause no boost whatsoever? I haven't had much time to even look at the car yet, so I'm sorry if this is vague. I just wanted to know because I was thinking I was having some bad i/c piping leaks or a bov leak before all this happened.

 

[liquordrunk]

could try a boost leak test... to see if your leaking

 

[foreverinvayne]

Well, i was thinking... if there was a leak in the piping big enough to cause me to not get any boost at all like this... then i should be able to hear it or notice it, wouldnt i? Or at least be able to hear the turbo spool up?

 

[oldman]

Check the turbo for shaft play and that it spins freely. Ask your dad if he left something out, like redlining or something.

 

[ZachM31]

yeah if you had a leak you would hear the turbo spool.. your boost gauge will also show what pressure the intake manifold is actually seeing, you would also notice the decrease in power... i need to make a leak tester whenever i go to home depot.. kind of sucks living out in the middle of nowhere.. you actually have to drive somewheres to get something.. if you can't get past 0 psi (atmospheric pressure) then i doubt it is a leak that big.. something isn't connected.. if a intercooler pipe blew off, your car wouldnt run.(had that happen while holding my engine wide open in 3rd gear passing someone i bet he was like "what the hell" when he saw me bog out and had to pull over haha) anyways, just check for shaft play, good possibility that excessive shaft play isn't allowing the turbo to spin as free as it should. i hope we're helping.

 

[liquordrunk]

i just said that he could try a leak test jsut to see where he was at with the whole situation is all. Understandably if the turbine blade are stuck or not spinning for some reason well then.

 

[ZachM31]

i'm not saying you are in the wrong for suggesting that, i was going to tell him to do that as well, but i saw your post before me... obviously something is leaking because he isn't producing any boost.. i didn't want to make it sound like a boost leak test was out of the question.. i am better at talking to someone face to face so they know if i am joking, optimistic, serious, things like that... now that i re-read what i posted i know what you are talking about though, i just wanted to clear things up.. i added to your reputation for the suggestion

 

[foreverinvayne]

Well, another thing I should have added was the fact that before this had happened I was starting to hear a decent blow off valve sound when i still have my stock bov diverted to the intake pipe still. And from what I've read taht could be caused by a decent sized leak itself. But I'm gonna see if i can't make a leak tester or borrow one from someone to try and get it all worked out. And when i get home tonight im definitely gonna take the intake pipe off either way and check for excessive shaft play and ease of turning and whatnot. Thanx a lot guys.

 

[Gators453]

i had that same problem, it wouldnt go above 0 but would read vac fine. my problem ended up being my intercooler was clogged and it was actually sucking air in throw the bov so it was getting just enough to run...so if nothing else is wrong thats my suggestion...hope you find the problem, i know how frusterating it is.

 

[foreverinvayne]

Hmmm, thanx, maybe i'll try that too. I just gotta find the time when it's light out and i can see to take it all apart and look at it all.