Welcome to the North American Subaru Impreza Owners Club Friday March 29, 2024
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
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.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 06-13-2011, 01:12 PM   #1
jacky599r
Scooby Specialist
 
Member#: 137631
Join Date: Jan 2007
Vehicle:
2006 WRX
Red

Default Back to Stock (with a couple of problems)

Hi Guys:

I have since returned to stock hardware less exhaust and a cold air intake. Further, I've also gotten my ECU flashed with a stock ROM. However, the car still behaves weird. On boost, part throttle or WOT, there seems to be a fluttering sound coming from the right side of the engine compartment. Also, the transition between boost and off boost isn't a smooth one.

May i know what could be the probable causes?

Jacky
* Registered users of the site do not see these ads.
jacky599r is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 06-13-2011, 01:15 PM   #2
sc00ter
Scooby Guru
 
Member#: 117767
Join Date: Jun 2006
Chapter/Region: RMIC
Location: Denver, CO
Vehicle:
2014 Audi S4
DP Stage 2 (~420whp)

Default

Assuming you mean that you left the CAI and exhaust on the car, my guess would be that the CAI with the stock tune is causing this issue.

Also, is your downpipe stock?
sc00ter is offline   Reply With Quote
Old 06-13-2011, 01:39 PM   #3
Spenk
Scooby Guru
 
Member#: 7164
Join Date: Jun 2001
Location: Arizona Bay
Vehicle:
2000 Miata LS
Evo Orange Mica (1/644)

Default

You need stock parts to run a stock map.

Spenk is offline   Reply With Quote
Old 06-13-2011, 02:28 PM   #4
2Fast4U1DAY
Scooby Specialist
 
Member#: 250152
Join Date: Jun 2010
Chapter/Region: MAIC
Location: Pennsylvania
Vehicle:
2006 WRX Limited
OBP

Default

Quote:
Originally Posted by jacky599r
Hi Guys:

I have since returned to stock hardware less exhaust and a cold air intake. Further, I've also gotten my ECU flashed with a stock ROM. However, the car still behaves weird. On boost, part throttle or WOT, there seems to be a fluttering sound coming from the right side of the engine compartment. Also, the transition between boost and off boost isn't a smooth one.

May i know what could be the probable causes?

Jacky
The fluttering is probably your wastegate trying to regulate boost this is normal.

The transition you are speaking of is probably the Closed Loop/ Open Loop fueling transition which as far as I know has never been smooth in the turbo Subaru's in their stock form.

Last edited by 2Fast4U1DAY; 06-13-2011 at 10:01 PM.
2Fast4U1DAY is offline   Reply With Quote
Old 06-13-2011, 03:08 PM   #5
Midevil
Scooby Specialist
 
Member#: 175065
Join Date: Mar 2008
Chapter/Region: MAIC
Location: MD
Vehicle:
2011 SWP WRX
INTERNET TOUGH GUYS? LOL

Default

You need to take the CAI off and replace with a stock intake system. CBE should be fine regardless.
Midevil is offline   Reply With Quote
Old 06-13-2011, 03:13 PM   #6
dsmtweaker
Scooby Specialist
 
Member#: 265405
Join Date: Nov 2010
Chapter/Region: MWSOC
Location: Traverse City Michigan
Vehicle:
2013 Audi
Black

Default

Quote:
Originally Posted by 2Fast4U1DAY View Post
The fluttering is probably your wastegate trying to regulate boost this is normal.
Agreed
dsmtweaker is offline   Reply With Quote
Old 06-13-2011, 06:58 PM   #7
IA Performance
Former Vendor
 
Member#: 25194
Join Date: Sep 2002
Chapter/Region: RMIC
Location: Boulder, CO
Vehicle:
2008 Forester XT 5mt
Dark Gray

Default

if the fluttering changes pitch from when the exhaust is cold to hot then you may have a leak at one of the pre turbo gaskets, most likely one of the 2 on the up-pipe. As others have also mentioned, there will be some wastegate door chatter sounds with an aftermarket downpipe. The bell mouth downpipes have some of the loudest chatter.

Stephen
IA Performance is offline   Reply With Quote
Old 06-13-2011, 07:40 PM   #8
wrx surfwagon
Scooby Specialist
 
Member#: 262719
Join Date: Nov 2010
Chapter/Region: NESIC
Location: Connecticut
Vehicle:
02 WRX
PSM with rust accents

Default

you should prob get tuned for all those bolt ons. by exhaust do you mean tbe or cbe?
wrx surfwagon is offline   Reply With Quote
Old 06-13-2011, 10:28 PM   #9
jacky599r
Scooby Specialist
 
Member#: 137631
Join Date: Jan 2007
Vehicle:
2006 WRX
Red

Default

Thanks for the prompt replies.
Well, my downpipe is stock and exhaust would be CBE (Fujitsubo). As for the transition, its really bad, I'm talking about "stages" of lag and punch between 2.5krpm to about 4.5krpm; it gets pretty jittery.
Is the wastegate supposed to sound like that? I remember i have the same intake,20g and a forge bpv and it did not make that kinda sound.
jacky599r is offline   Reply With Quote
Old 06-13-2011, 11:38 PM   #10
IA Performance
Former Vendor
 
Member#: 25194
Join Date: Sep 2002
Chapter/Region: RMIC
Location: Boulder, CO
Vehicle:
2008 Forester XT 5mt
Dark Gray

Default

I'm leaning towards a mechanical issue versus wastegate door flutter given the stock DP. Stock DPs tend to make zero noise. Air leaks on the pressure side of the turbo will make noise, as will leaks between the turbo outlet and intake valves (throughout IC and intake manifold). Time to start with a boost leak test. A vacuum leak will create A/F issues that could result in the jittery sensation you feel.
IA Performance is offline   Reply With Quote
Old 06-14-2011, 06:15 AM   #11
2Fast4U1DAY
Scooby Specialist
 
Member#: 250152
Join Date: Jun 2010
Chapter/Region: MAIC
Location: Pennsylvania
Vehicle:
2006 WRX Limited
OBP

Default

Quote:
Originally Posted by IA Performance
I'm leaning towards a mechanical issue versus wastegate door flutter given the stock DP. Stock DPs tend to make zero noise. Air leaks on the pressure side of the turbo will make noise, as will leaks between the turbo outlet and intake valves (throughout IC and intake manifold). Time to start with a boost leak test. A vacuum leak will create A/F issues that could result in the jittery sensation you feel.
I disagree with your first statement. My 06 flutters ALOT. Stock turbo, stock DP, stock tune, all new gaskets, and no leaks.

Vacuum leaks will also cause the engine to Idle rough.
2Fast4U1DAY is offline   Reply With Quote
Old 06-14-2011, 05:40 PM   #12
IA Performance
Former Vendor
 
Member#: 25194
Join Date: Sep 2002
Chapter/Region: RMIC
Location: Boulder, CO
Vehicle:
2008 Forester XT 5mt
Dark Gray

Default

You are entitled to disagree, I too own a 2006, it is actually my 3rd one, and did not have a note worthy flutter noise from the wastegate. This was on a WRX, STi, and again with a WRX. All with Stock downpipes. I later changed to a bellmouth which brought in some flutter/chatter from the wastegate.
IA Performance is offline   Reply With Quote
Old 06-14-2011, 05:46 PM   #13
IA Performance
Former Vendor
 
Member#: 25194
Join Date: Sep 2002
Chapter/Region: RMIC
Location: Boulder, CO
Vehicle:
2008 Forester XT 5mt
Dark Gray

Default

Check to make sure there are no leaks between the MAF and the turbo inlet. Sometimes the o-ring around the MAF fails, especially if an intake has been put on the car. If this leaks you may end up with similar symptoms.
IA Performance is offline   Reply With Quote
Old 06-14-2011, 08:03 PM   #14
gathermewool
Scooby Specialist
 
Member#: 143624
Join Date: Mar 2007
Chapter/Region: NESIC
Location: New England
Vehicle:
14 FXTT (hers)
15 Legacy 2.5i Prem (his)

Default

Quote:
Originally Posted by IA Performance View Post
You are entitled to disagree, I too own a 2006, it is actually my 3rd one, and did not have a note worthy flutter noise from the wastegate. This was on a WRX, STi, and again with a WRX. All with Stock downpipes. I later changed to a bellmouth which brought in some flutter/chatter from the wastegate.
Did you have a CAI on any of these? My '08 went from dead quiet to flutter city after installing an AEM CAI. The flutter should sound consistent if you're accelerating at a relatively constant rate, and should not be present at lower boost levels. Is this the case?

Finally, by flashing back to the stock ROM do you mean that you have a stock-like map or that you unmarried an AP? If some one sent you a "stock" map, is there a chance that it actually wasn't?
gathermewool is offline   Reply With Quote
Old 03-09-2014, 11:55 AM   #15
Raven999
Scooby Newbie
 
Member#: 381768
Join Date: Feb 2014
Default

Does the fluttering sound sound like a chattering either? Like rapidly tapping a coin on a hardwood table?
Raven999 is offline   Reply With Quote
Old 03-09-2014, 12:00 PM   #16
Raven999
Scooby Newbie
 
Member#: 381768
Join Date: Feb 2014
Default

I ask because I have this issue with mine, and I know turbo systems well enough to understand leaks and or cracks in turbocharged exhaust systems may or will cause chattering sounds. I own an 07 STi sedan, stock. (New project car and daily driver) and due to the rough winter that thankfully recently ended here in Spokane Washington, I feel my cars insides have taken much of a beating as well.
Raven999 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
Moving back home to PA in a couple of weeks. Robson Mid Atlantic Impreza Club -- MAIC 2 10-31-2009 11:35 PM
going back to stock so a couple parts for sale shoodoggy Engine/Power/Exhaust 24 02-11-2008 02:16 PM
Selling A Couple Things...Going Back To Stock... coleman_a SCIC Private Classifieds 0 03-30-2007 02:35 AM
Going back to stock and have a couple of questions... Ldogdotcom Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 1 11-21-2005 11:33 AM
Back to Stock EM with An Intake for A Couple Days...Problem? Red Rexx Engine Management & Tuning 2 03-10-2005 10:57 PM

All times are GMT -4. The time now is 05:34 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2024 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.

When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission
Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.