Welcome to the North American Subaru Impreza Owners Club Saturday May 23, 2015
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 2.5L Turbo Powertrain (EJ Series Factory 2.5L Turbo)

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 03-16-2012, 04:02 AM   #1
CobbsSTI
Scooby Specialist
 
Member#: 245242
Join Date: Apr 2010
Chapter/Region: MWSOC
Location: Morris,IL
Vehicle:
2006 STI
E85 Power

Default

Can an exhaust leak pre turbo cause a stutter like affect or something similar? I think its a leak at one of the flanges pre turbo, it seems that once the exhaust heats up and expands at one of these flanges the leak stops and so does the stutter, its only on start up when the exhaust is cold, and there is no boost/vacuum leaks. Suggestions/ideas?
* Registered users of the site do not see these ads.
CobbsSTI is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 03-16-2012, 01:55 PM   #2
flycaster
Scooby Specialist
 
Member#: 60142
Join Date: Apr 2004
Location: Bend, OR
Vehicle:
2011 WRX
Grey

Default

Put it up on a lift and take a look. If there is a leak between the exhaust manifold and the turbo, it'll be easy to see - just look for carbon splatter. Is your boost spool-up noticeably slower?
flycaster is offline   Reply With Quote
Old 03-16-2012, 02:00 PM   #3
APM Tuned
NASIOC Vendor
 
Member#: 282460
Join Date: May 2011
Chapter/Region: MWSOC
Location: Villa Park, IL
Vehicle:
2005 Evo-STI
R.R.-WRB

Default

what he said, there will be carbon build up where the gaskets or flanges have failed and also like he stated, there will be a decrease in spool up efficiency, a bit more noise and slower response in power.

Also, being that the leak is in front of you, the faint exhaust gas smells will enter the cabin with windows closed and no ventilation from A/C or heat.

-Mark
APM Tuned is offline   Reply With Quote
Old 03-16-2012, 02:25 PM   #4
CobbsSTI
Scooby Specialist
 
Member#: 245242
Join Date: Apr 2010
Chapter/Region: MWSOC
Location: Morris,IL
Vehicle:
2006 STI
E85 Power

Default

Thanks guys, boost seems to be ok when the exhaust heats up, like I said once it heats up the leak goes away cause of the metal expanding. I've only got into boost once the cat heats up pretty good and it seems fine, havent got on it when it was cold and leaking to tell if boost was lagging
CobbsSTI is offline   Reply With Quote
Old 03-16-2012, 02:29 PM   #5
CobbsSTI
Scooby Specialist
 
Member#: 245242
Join Date: Apr 2010
Chapter/Region: MWSOC
Location: Morris,IL
Vehicle:
2006 STI
E85 Power

Default

On first start of the day ill let it warm up a lil before I go, I looked under the car and noticed that there was some water coming out of the flange where the header meets the up pipe so I'm guessing the leak is there. The water is just condensation built up in the exhaust from sitting over night so I know that's ok.
CobbsSTI is offline   Reply With Quote
Old 03-16-2012, 07:50 PM   #6
flycaster
Scooby Specialist
 
Member#: 60142
Join Date: Apr 2004
Location: Bend, OR
Vehicle:
2011 WRX
Grey

Default

OK, so what makes you think it has a "cold" leak? Can you hear it and see some carbon evidence somewhere? Frankly, that water you see could easily be dripping down from somewhere else.

Also, what's this "stutter" thing you mentioned? A small pre-turbo exhaust leak will just cause slower spool-up; it shouldn't make the car run rough, IF that's what you're trying to say. Tell us more.
flycaster is offline   Reply With Quote
Old 03-16-2012, 10:54 PM   #7
CobbsSTI
Scooby Specialist
 
Member#: 245242
Join Date: Apr 2010
Chapter/Region: MWSOC
Location: Morris,IL
Vehicle:
2006 STI
E85 Power

Default

Quote:
Originally Posted by flycaster
OK, so what makes you think it has a "cold" leak? Can you hear it and see some carbon evidence somewhere? Frankly, that water you see could easily be dripping down from somewhere else.

Also, what's this "stutter" thing you mentioned? A small pre-turbo exhaust leak will just cause slower spool-up; it shouldn't make the car run rough, IF that's what you're trying to say. Tell us more.
Like I said the exhaust leaks when it isn't fully warmed up, its leaking at the header to up pipe flange and yes I do see carbon there, I can he it but when it warms up fully the sound and the slight stutter goes away, now the stutter only happens when I get on it and the exhaust isn't all the way warmed up, it doesn't leak when its warmed up all the way cause of the metal expanding and sealing the leak.
CobbsSTI is offline   Reply With Quote
Old 03-16-2012, 11:02 PM   #8
CobbsSTI
Scooby Specialist
 
Member#: 245242
Join Date: Apr 2010
Chapter/Region: MWSOC
Location: Morris,IL
Vehicle:
2006 STI
E85 Power

Default

I've watched the flange closely on start up for the first time of the day and the water is dripping from the flange cause of the condensation built up in the exhaust and its leaking through the leak in the flange where the gasket is, so my question is can this leak cause a slight stutter if not fixed, cause it only does it when the sound of the leak is there then goes away once warmed up and the sound of the leak goes away.
CobbsSTI is offline   Reply With Quote
Old 03-17-2012, 01:45 AM   #9
flycaster
Scooby Specialist
 
Member#: 60142
Join Date: Apr 2004
Location: Bend, OR
Vehicle:
2011 WRX
Grey

Default

The question is irrelevant. You have a leak, fix it.
flycaster is offline   Reply With Quote
Old 03-17-2012, 03:28 AM   #10
Coreycarlile911
Scooby Specialist
 
Member#: 282614
Join Date: May 2011
Chapter/Region: NWIC
Location: Spokane Washington
Vehicle:
2006 Wrx sti
Black pearl

Default

Quote:
Originally Posted by CobbsSTI View Post
Can an exhaust leak pre turbo cause a stutter like affect or something similar? I think its a leak at one of the flanges pre turbo, it seems that once the exhaust heats up and expands at one of these flanges the leak stops and so does the stutter, its only on start up when the exhaust is cold, and there is no boost/vacuum leaks. Suggestions/ideas?
I have a 06 sti and this sounds like what I got going on I get a exhaust smell at wot and my spool up seems to be a bit slow where is the first places I should check for a leak the car still pulls hard and runs fine but the smell I figured was from catless.
Coreycarlile911 is offline   Reply With Quote
Old 03-17-2012, 03:34 AM   #11
Coreycarlile911
Scooby Specialist
 
Member#: 282614
Join Date: May 2011
Chapter/Region: NWIC
Location: Spokane Washington
Vehicle:
2006 Wrx sti
Black pearl

Default

Quote:
Originally Posted by APM Racing View Post
what he said, there will be carbon build up where the gaskets or flanges have failed and also like he stated, there will be a decrease in spool up efficiency, a bit more noise and slower response in power.

Also, being that the leak is in front of you, the faint exhaust gas smells will enter the cabin with windows closed and no ventilation from A/C or heat.

-Mark
I prob should have been asking you this question from the post above I quoted the wrong person also the exhaust smell is random regardless of hot or cold so could this be something other than leak?
Coreycarlile911 is offline   Reply With Quote
Old 03-17-2012, 10:19 AM   #12
flycaster
Scooby Specialist
 
Member#: 60142
Join Date: Apr 2004
Location: Bend, OR
Vehicle:
2011 WRX
Grey

Default

Does this happen all the time, or perhaps right after oil changes? Do you see any evidence of small oil leak(s) anywhere (floor drips, oil on the cross member, etc.)? Is everything tight and well sealed from the exhaust manifold to the tail pipe?
flycaster is offline   Reply With Quote
Old 03-17-2012, 02:31 PM   #13
Coreycarlile911
Scooby Specialist
 
Member#: 282614
Join Date: May 2011
Chapter/Region: NWIC
Location: Spokane Washington
Vehicle:
2006 Wrx sti
Black pearl

Default

Quote:
Originally Posted by flycaster
Does this happen all the time, or perhaps right after oil changes? Do you see any evidence of small oil leak(s) anywhere (floor drips, oil on the cross member, etc.)? Is everything tight and well sealed from the exhaust manifold to the tail pipe?
No oil leaks that I can see but I have to borrow ramps and tools from my friend so I havent gotten to check yet so was wondering of spots to check first
Coreycarlile911 is offline   Reply With Quote
Old 12-11-2012, 08:58 PM   #14
vhsc22
Scooby Newbie
 
Member#: 217417
Join Date: Jul 2009
Chapter/Region: South East
Location: Birmingham, AL
Vehicle:
2005 STI
PSM

Default

I think I'm having this problem..
vhsc22 is offline   Reply With Quote
Old 04-13-2013, 03:02 PM   #15
nutinbuthehits
Scooby Newbie
 
Member#: 214758
Join Date: Jun 2009
Default

bump from the dead! im also having this problem. this exhaust leak IM HOPING causes the slight stutter/hesitation that you talking about, because i have it also
nutinbuthehits is offline   Reply With Quote
Old 05-09-2013, 12:36 PM   #16
Lurk
Scooby Specialist
 
Member#: 222686
Join Date: Sep 2009
Chapter/Region: SCIC
Vehicle:
95 WRX Coupe

Default

Yeah me too

Upon started up / warm = no noises, weird idling, smells...car is great!

Just when I drive and I give it gas OR go into boost the car hesitates, sputters, hits fuel cut (im on the gas pedal and nothing happens) then the car lunges forwards, then pauses and goes again... kinda builds boost then hesitates /pauses / sputters

So If i drive like a grandma and dont go up hills im fine...

I have a few silly parts on the car...came with the car

Aftermarket = td05 turbo with after market wastegate, flex up-pipe, HKS blitz blow off valve,
OEM parts = headers, turbo back exhaust, gaskets, intercooler, I just rebuilt the whole engine so thats tits

Im thinking its the up-pipe, wastegate, BOV or the turbo inlet...its kinda busted or its that cheap turbo... If I find anything Ill let you know
Lurk is offline   Reply With Quote
Old 05-10-2013, 02:31 AM   #17
locdogg
Scooby Newbie
 
Member#: 325793
Join Date: Jul 2012
Chapter/Region: International
Location: Gold Coast/Brisbane, Australia
Vehicle:
2012 WRX
Pearl White

Default

Mine has oil splattered over a hose from the intercooler
locdogg is offline   Reply With Quote
Old 05-10-2013, 09:54 AM   #18
roadtrip1098
Scooby Newbie
 
Member#: 185688
Join Date: Jul 2008
Chapter/Region: NESIC
Location: Maine
Vehicle:
2006 STi
WR Blue

Default

There are 2 very common gaskets that go bad. A two bolt one fromt he header to up-pipe and a 3 bolt one from the up-pipe to the turbo.

Jerky behavior, weird idle usually points to a vacuum leak. Check your PCV hoses, also the line from the intake manifold to the recirc valve. Both pretty common.
roadtrip1098 is offline   Reply With Quote
Old 05-10-2013, 10:28 AM   #19
nutinbuthehits
Scooby Newbie
 
Member#: 214758
Join Date: Jun 2009
Default

the uppipe to turbo gasket was the culprit for me. i changed it and havent had any problems since
nutinbuthehits is offline   Reply With Quote
Old 06-29-2013, 01:34 PM   #20
johnblahuta88
Scooby Specialist
 
Member#: 221614
Join Date: Aug 2009
Default

mine is having a low hissing at a idle. its annoying. I need to take off the heat shields and check it out

https://www.youtube.com/watch?v=AIzPzDzDcKM
johnblahuta88 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

Similar Threads
Thread Thread Starter Forum Replies Last Post
Exhaust leak? or turbo spooling? eep4_dc5 Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 6 06-20-2010 11:16 AM
Exhaust leak after turbo swap? theprodgalson Newbies & FAQs 8 03-03-2010 01:32 AM
Pre Turbo exhaust leak...... abosworth Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 5 05-16-2007 10:15 AM
Exhaust leak or turbo noise? 06AspenWhite Factory 2.5L Turbo Powertrain (EJ Series Factory 2.5L Turbo) 10 10-29-2006 11:53 PM
occasional exhaust leak after turbo Jeff02WRX Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 4 02-21-2003 07:40 PM


All times are GMT -4. The time now is 11:59 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2015 Axivo Inc.
Copyright ©1999 - 2015, North American Subaru Impreza Owners Club, Inc.