Welcome to the North American Subaru Impreza Owners Club Wednesday July 30, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Factory 2.0L Turbo Powertrain

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 04-26-2014, 12:01 PM   #1
loofer
Scooby Newbie
 
Member#: 342743
Join Date: Jan 2013
Chapter/Region: MWSOC
Location: Michigan
Vehicle:
2002 WRX
Silver

Default Initial Boost is good, but when I shift it falls on it's face!

So randomly last night I started making no boost on my 2002 WRX.

Here's the skinny:

As I start from a dead stop, I punch it and it holds perfect boost through 1st gear. Then as I shift into 2nd the suby literally falls on it's face and I making barely over zero PSI. But, if I decelerate (let off the throttle) then accelerate again boost is back. Then I go to shift and nothing.

It is extremely consistent, so here are the list of my mods:
2.1 Stroker (Forged internals)
11mm STI Oil pump
HKS SSQV Original Blow-off valve
3 inch BPM exhaust from the Turbo back with High flow cat.

The Turbo is the stock bugeye turbo
Stock fuel system
Stock intake

Any ideas on what this issue might be or where I should start looking? It feels like boost leak, but then again why does it hold boost until I shift every time? Could it be the Blow-off valve remaining slightly open after I shift? Wastegate Spring issue?

I would love to hear your input! Let me know Friends!
* Registered users of the site do not see these ads.
loofer is offline   Reply With Quote
Old 04-26-2014, 12:26 PM   #2
Andrewxxcarlson
Scooby Specialist
 
Member#: 316415
Join Date: Apr 2012
Location: Elk Grove, CA
Vehicle:
2006 WRX
WRB

Default

I'd start lookin at that bov
Andrewxxcarlson is offline   Reply With Quote
Old 04-26-2014, 01:04 PM   #3
loofer
Scooby Newbie
 
Member#: 342743
Join Date: Jan 2013
Chapter/Region: MWSOC
Location: Michigan
Vehicle:
2002 WRX
Silver

Default

Ya good call, I'll give the throttle cable a few pulls and see if their are any gaps as it closes. If that is the case should I try and lube the shaft in the HKS?
loofer is offline   Reply With Quote
Old 04-26-2014, 04:02 PM   #4
loofer
Scooby Newbie
 
Member#: 342743
Join Date: Jan 2013
Chapter/Region: MWSOC
Location: Michigan
Vehicle:
2002 WRX
Silver

Default

So I revved the suby a few times, drove it down the rode an back. I didn't notice any issues with the HKS BOV, but no I hear some small scretching from the turbo

It's a sad day.. .. ...

Any recommendations for a turbo for a 2.1 build, lol? Only looking for around 300hp and would like to keep the fuel system stock if possible.
loofer is offline   Reply With Quote
Old 04-26-2014, 07:15 PM   #5
Shiftace420
Scooby Newbie
 
Member#: 383633
Join Date: Mar 2014
Chapter/Region: RMIC
Location: Yampa, CO
Vehicle:
2002 Impreza WRX
Silver

Default

I second the BOV. You would hear extra spool from the turbo if its leaking. Also if your turbo is bad, its probably bad all the time and will not get better after you let off.

Sounds like the BOV is sticking after shifts and is seating when you let off(go into vacuum mode)

I don't think this is your issue but if it is: If your going to vary from the stock turbo plan on getting fuel system upgrades. You can cheat a little with fuel pressure and injector duty to a point but your best off to just do it right. Should pull the downpipe and check the shaft play before you condemn the turbo.
Shiftace420 is online now   Reply With Quote
Old 04-26-2014, 08:12 PM   #6
loofer
Scooby Newbie
 
Member#: 342743
Join Date: Jan 2013
Chapter/Region: MWSOC
Location: Michigan
Vehicle:
2002 WRX
Silver

Default

Solid advice! I'll probably do that tomorrow to check. I truly was hoping it was the bov, but when I started hearing what sounded like ball bearings going.

Here check it out:https://www.youtube.com/watch?v=0d7j-_yhzVo
loofer is offline   Reply With Quote
Old 04-26-2014, 09:39 PM   #7
Shiftace420
Scooby Newbie
 
Member#: 383633
Join Date: Mar 2014
Chapter/Region: RMIC
Location: Yampa, CO
Vehicle:
2002 Impreza WRX
Silver

Default

Does sound a little odd. Video helps alot thanks for posting. Better pull the DP and check for sure.

I have never seen a turbo boost like that lol. Most I see are pretty much destroyed and don't boost at all or have terrible sound while boosting but still boost everytime not interminantly like that.

If its your turbo i would recommend you send it in to a good rebuilder. Usually the cheapest option to get a brand new rebuilt turbo with piece of mind. Otherwise the TD04 is widely availble used but your still guessing at condition or rebuilding it anyways.
Shiftace420 is online now   Reply With Quote
Old 04-27-2014, 12:13 PM   #8
loofer
Scooby Newbie
 
Member#: 342743
Join Date: Jan 2013
Chapter/Region: MWSOC
Location: Michigan
Vehicle:
2002 WRX
Silver

Default

So I pulled the downpipe off after church. The turbine shaft is not loose at all! Woot! Zero play, however, the wastegate vlave next to the turbine is quite loose. Check the picture out to see what I'm talking about.

I am guessing that is suppose to seal really nice and be tight. Any ideas how to get that wastegate valve fixed?

[IMG][/IMG]

Last edited by loofer; 04-27-2014 at 01:04 PM.
loofer is offline   Reply With Quote
Old 04-27-2014, 01:16 PM   #9
Shiftace420
Scooby Newbie
 
Member#: 383633
Join Date: Mar 2014
Chapter/Region: RMIC
Location: Yampa, CO
Vehicle:
2002 Impreza WRX
Silver

Default

Adjust the preload on the spring? Should see about 7psi to crack and 10psi to open full if you hook a mityvac in pressure mode to the diaphram.

Is the arm still hooked up? They can strip out or fall off after time.
Shiftace420 is online now   Reply With Quote
Old 04-27-2014, 01:24 PM   #10
loofer
Scooby Newbie
 
Member#: 342743
Join Date: Jan 2013
Chapter/Region: MWSOC
Location: Michigan
Vehicle:
2002 WRX
Silver

Default

By arm I'm assuming the arm from the spring down to this valve? And their is suppose to be no play on that valve correct? So for the Noob questions. I know motors, but not internal workings of the turbo.

Last edited by loofer; 04-27-2014 at 01:38 PM.
loofer is offline   Reply With Quote
Old 04-27-2014, 02:03 PM   #11
loofer
Scooby Newbie
 
Member#: 342743
Join Date: Jan 2013
Chapter/Region: MWSOC
Location: Michigan
Vehicle:
2002 WRX
Silver

Default

I just pulled on the wastegate arm and it does not function smoothly. I simulated it opening and closing multiple times and it would leave the valve open sometimes and other times it would close. very inconsistent! Sound like a bad waste gate?
loofer is offline   Reply With Quote
Old 04-27-2014, 02:57 PM   #12
Shiftace420
Scooby Newbie
 
Member#: 383633
Join Date: Mar 2014
Chapter/Region: RMIC
Location: Yampa, CO
Vehicle:
2002 Impreza WRX
Silver

Default

Yup that's your problem. Also the arm can be turned and cause binding with the diaphram. You should disconnect the arm and move the wastegate. If its crusty or sandy feeling your wastegate is sticking for sure.
Shiftace420 is online now   Reply With Quote
Old 04-27-2014, 03:31 PM   #13
loofer
Scooby Newbie
 
Member#: 342743
Join Date: Jan 2013
Chapter/Region: MWSOC
Location: Michigan
Vehicle:
2002 WRX
Silver

Default

Ya I just removed that C clip on the actuator arm, and the Wastegate flap itself seem to stick a lot as I freely moved it back and forth. How would I go about actually replacing that wastegate flap?? I can easily replace the actuator, but I'm not sure on the flapper.
loofer is offline   Reply With Quote
Old 04-27-2014, 04:49 PM   #14
loofer
Scooby Newbie
 
Member#: 342743
Join Date: Jan 2013
Chapter/Region: MWSOC
Location: Michigan
Vehicle:
2002 WRX
Silver

Default

Or is there a way to polish up the "seating" of that flapper to the turbo housing and smooth out the opening & closing action of that flap?
loofer is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -4. The time now is 11:55 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.