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 General > Newbies & FAQs

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 10-06-2012, 01:01 PM   #1
pocketdrummer
Scooby Newbie
 
Member#: 197301
Join Date: Dec 2008
Chapter/Region: TXIC
Location: Austin, TX
Vehicle:
2005 WRX STI
W R Blue (02C)

Default Rough sound at 1500rpm

Recently, after upgrading to a Cobb Downpipe, I experienced a slew of issues. The was running fine after the install, but shortly afterwards the bolt holding the alternator broke. After working the bolt out and reinstalling the alternator I had a vibration issue in the pedal around 1500 and 3000 rpm. We replaced the spark plugs and pcv, then cleaned the throttle body and iacv. We also tightened two intake hoses that were completely loose.

After driving for a little while, I thought the problems were over. The vibration in the pedal was gone. However, a few days ago a new (or modified) issued arose. On a cold start, the engine idles irregularly and makes a strange sound at 1500rpm accompanied by a little bit of vibration in the pedal. Oddly, this problem almost completely resolves itself when the engine warms up.

What could cause something like this? I don't want to just throw parts at it, but I'm nearing the end of my abilities to do this myself.
pocketdrummer is offline   Reply With Quote
Old 10-06-2012, 01:15 PM   #2
dirtyrex1992
Scooby Newbie
 
Member#: 277548
Join Date: Mar 2011
Chapter/Region: NESIC
Location: Raynham, MA
Vehicle:
2011 Subaru wrx
Silver

Default

Are you tuned for the downpipe?
dirtyrex1992 is offline   Reply With Quote
Old 10-06-2012, 05:02 PM   #3
pocketdrummer
Scooby Newbie
 
Member#: 197301
Join Date: Dec 2008
Chapter/Region: TXIC
Location: Austin, TX
Vehicle:
2005 WRX STI
W R Blue (02C)

Default

Quote:
Originally Posted by dirtyrex1992 View Post
Are you tuned for the downpipe?
Nope. I didn't think it was required because the Downpipe FAQs said the '02 could run without it. I planned on getting one after I installed the up-pipe and cat-back.
pocketdrummer is offline   Reply With Quote
Old 10-06-2012, 08:04 PM   #4
pocketdrummer
Scooby Newbie
 
Member#: 197301
Join Date: Dec 2008
Chapter/Region: TXIC
Location: Austin, TX
Vehicle:
2005 WRX STI
W R Blue (02C)

Default

Any ideas?

99,000mi
New Alternator
New Accessory belts
New PCV
New Spark Plugs
Just cleaned throttle body
Just cleaned IACV

What's left to try?
pocketdrummer is offline   Reply With Quote
Old 10-06-2012, 09:51 PM   #5
RoadKillDMD
Scooby Specialist
 
Member#: 284792
Join Date: Jun 2011
Chapter/Region: RMIC
Location: Vanilla Valley, CO
Vehicle:
2011 STI
Plasma Blue Pearl

Default

Clean your MAF sensor
RoadKillDMD is offline   Reply With Quote
Old 10-06-2012, 09:58 PM   #6
pocketdrummer
Scooby Newbie
 
Member#: 197301
Join Date: Dec 2008
Chapter/Region: TXIC
Location: Austin, TX
Vehicle:
2005 WRX STI
W R Blue (02C)

Default

Quote:
Originally Posted by RoadKillDMD View Post
Clean your MAF sensor
I did that an 3-5k mi ago, but I guess that couldn't hurt. Would that be something that got better as the car warmed up, though?
pocketdrummer is offline   Reply With Quote
Old 10-06-2012, 10:06 PM   #7
Napalm3nema
Scooby Specialist
 
Member#: 263954
Join Date: Nov 2010
Location: Houston, TX
Vehicle:
2014 EVO Yes, EVO
Wicked White

Default

I'd just spring for the up-pipe now and get it tuned. You don't need to get tuned for the exhaust.

That's probably why your car is pissed, even though 'technically' it shouldn't be. Then again, I don't know how smooth 02/03's run with a downpipe and no tune. <shrug>
Napalm3nema is offline   Reply With Quote
Old 10-07-2012, 01:01 AM   #8
pocketdrummer
Scooby Newbie
 
Member#: 197301
Join Date: Dec 2008
Chapter/Region: TXIC
Location: Austin, TX
Vehicle:
2005 WRX STI
W R Blue (02C)

Default

Quote:
Originally Posted by Napalm3nema View Post
I'd just spring for the up-pipe now and get it tuned. You don't need to get tuned for the exhaust.

That's probably why your car is pissed, even though 'technically' it shouldn't be. Then again, I don't know how smooth 02/03's run with a downpipe and no tune. <shrug>
Could it be a timing issue? I'm only 6k away from the 105k maintenance. Though, it did seem to come on quite suddenly, so I'm not sure if that's it.

Last edited by pocketdrummer; 10-07-2012 at 01:10 AM.
pocketdrummer is offline   Reply With Quote
Old 10-07-2012, 11:14 AM   #9
Napalm3nema
Scooby Specialist
 
Member#: 263954
Join Date: Nov 2010
Location: Houston, TX
Vehicle:
2014 EVO Yes, EVO
Wicked White

Default

Don't know if that could be a factor, it just seems that the only thing major you changed before having this issue was adding the downpipe.

Perhaps someone with first hand experience with an 02/03 could chime in if they have run their cars without a tune to let you know if this behavior is expected?
Napalm3nema is offline   Reply With Quote
Old 10-07-2012, 02:47 PM   #10
pocketdrummer
Scooby Newbie
 
Member#: 197301
Join Date: Dec 2008
Chapter/Region: TXIC
Location: Austin, TX
Vehicle:
2005 WRX STI
W R Blue (02C)

Default

Quote:
Originally Posted by Napalm3nema View Post
Don't know if that could be a factor, it just seems that the only thing major you changed before having this issue was adding the downpipe.

Perhaps someone with first hand experience with an 02/03 could chime in if they have run their cars without a tune to let you know if this behavior is expected?
Would it sound like that immediately after the installation if that were the case? It was fine for a few days before that damn bolt broke.
pocketdrummer is offline   Reply With Quote
Old 10-07-2012, 03:55 PM   #11
DZXN
Scooby Newbie
 
Member#: 306186
Join Date: Jan 2012
Chapter/Region: SCIC
Location: Costa Mesa
Vehicle:
2002 Subaru WRX
PSM

Default

I'm guessing it's just running rough from the added flow of the DP with/o the tune. You could reset the ecu and see if it goes back to running like when you first put it on. Mine ran a little rougher after my dp install before tune when it was cold. I would look for a up pipe if for nothing else besides safety and spool 500 rpms quicker and get a tune to stage 2. If you don't have a tatrix, ask around in txic and see if some one can help for beer money and get a xpt tune.
DZXN is offline   Reply With Quote
Old 10-08-2012, 07:26 PM   #12
pocketdrummer
Scooby Newbie
 
Member#: 197301
Join Date: Dec 2008
Chapter/Region: TXIC
Location: Austin, TX
Vehicle:
2005 WRX STI
W R Blue (02C)

Default

Noticed a new strange noise in the engine bay right before the car revs up. This is with the car warmed up. Does anyone know what that is?


Last edited by pocketdrummer; 10-08-2012 at 08:02 PM.
pocketdrummer is offline   Reply With Quote
Old 10-08-2012, 08:26 PM   #13
424wrx
Scooby Specialist
 
Member#: 171948
Join Date: Feb 2008
Chapter/Region: Tri-State
Location: new york
Vehicle:
08 wrx vf52,stg3
11 forester,14 legacy dd

Default

that does not sound good.
424wrx is offline   Reply With Quote
Old 10-08-2012, 08:47 PM   #14
pocketdrummer
Scooby Newbie
 
Member#: 197301
Join Date: Dec 2008
Chapter/Region: TXIC
Location: Austin, TX
Vehicle:
2005 WRX STI
W R Blue (02C)

Default

Quote:
Originally Posted by 424wrx View Post
that does not sound good.
Tell me about it...
That wasn't even the sound I was looking for. That's something else. Ugh...

Last edited by pocketdrummer; 10-08-2012 at 09:11 PM.
pocketdrummer is offline   Reply With Quote
Old 10-16-2012, 09:46 PM   #15
pocketdrummer
Scooby Newbie
 
Member#: 197301
Join Date: Dec 2008
Chapter/Region: TXIC
Location: Austin, TX
Vehicle:
2005 WRX STI
W R Blue (02C)

Default

Here's the sound I'm worried about. The first rev is out of gear, the last part is in gear.


Last edited by pocketdrummer; 10-16-2012 at 10:07 PM.
pocketdrummer is offline   Reply With Quote
Old 10-16-2012, 11:15 PM   #16
brew02wrx
Scooby Specialist
 
Member#: 259970
Join Date: Oct 2010
Chapter/Region: Tri-State
Location: brewster, NY
Vehicle:
2002 wrx cobb stg2+
psm proper fitment

Default

Quote:
Originally Posted by Napalm3nema
Don't know if that could be a factor, it just seems that the only thing major you changed before having this issue was adding the downpipe.

Perhaps someone with first hand experience with an 02/03 could chime in if they have run their cars without a tune to let you know if this behavior is expected?
I did for a week, def didn't have these types of issues with 133k on the clock

Sounds like its something internal, better do a compression test and a leakdown test and get a datalog for us to see what your ecu is doing
brew02wrx is offline   Reply With Quote
Old 10-17-2012, 12:10 AM   #17
SNE2040
Scooby Specialist
 
Member#: 72195
Join Date: Oct 2004
Chapter/Region: Tri-State
Location: NJ
Vehicle:
2015 WRX
ISM

Default

video 1 sounds like rod knock...
video 2 sounds like your up-pipe heatshield broke loose
SNE2040 is offline   Reply With Quote
Old 10-17-2012, 03:58 AM   #18
pocketdrummer
Scooby Newbie
 
Member#: 197301
Join Date: Dec 2008
Chapter/Region: TXIC
Location: Austin, TX
Vehicle:
2005 WRX STI
W R Blue (02C)

Default

Quote:
Originally Posted by SNE2040 View Post
video 1 sounds like rod knock...
video 2 sounds like your up-pipe heatshield broke loose
The 2nd videos issue improves substantially after the car heats up. Makes no sense.
pocketdrummer is offline   Reply With Quote
Old 10-17-2012, 10:06 AM   #19
Dat8687
Scooby Specialist
 
Member#: 243261
Join Date: Apr 2010
Chapter/Region: TXIC
Location: Forney
Vehicle:
2004 WRX
Java black pearl

Default

A downpipe doesnt cause the problems you stated unless there were other issues first or something was damaged on install
Dat8687 is offline   Reply With Quote
Old 10-17-2012, 12:25 PM   #20
Tdaz250
Scooby Newbie
 
Member#: 310744
Join Date: Feb 2012
Chapter/Region: NWIC
Vehicle:
02 WRX
WRB

Default

Take the car to a reputable shop around you and have them figure it out. I did my uppipe and downpipe at the same time and drove my car about 25 miles untuned to have the tune done and it never did any of this. Mines an 02. Also if it was a timing issue you would probably be throwing a misfire code.
Tdaz250 is offline   Reply With Quote
Old 10-18-2012, 02:33 AM   #21
mybbyselena
Scooby Newbie
 
Member#: 334734
Join Date: Oct 2012
Default

My 04 sti makes a very similar noise to the noise in video 2. idk what it is either.
mybbyselena is offline   Reply With Quote
Old 10-18-2012, 11:08 PM   #22
SNE2040
Scooby Specialist
 
Member#: 72195
Join Date: Oct 2004
Chapter/Region: Tri-State
Location: NJ
Vehicle:
2015 WRX
ISM

Default

Quote:
Originally Posted by mybbyselena View Post
My 04 sti makes a very similar noise to the noise in video 2. idk what it is either.
aftermarket downpipe?

My old 04 STI did as well... heatshield broke off the uppipe weld tab and rattled
SNE2040 is offline   Reply With Quote
Old 10-19-2012, 07:05 AM   #23
FCmaniac
Scooby Specialist
 
Member#: 142029
Join Date: Feb 2007
Chapter/Region: Tri-State
Location: Lehigh Valley, PA
Vehicle:
2013 Forester
2004 STi, 1991 Miata BRG

Default

video 1 to me doesn't sound like rod knock... it sounds like t belt tensioner

video 2 sounds like up heatshield. My 04's had the same issue... replaced up and its gone. And when the exhaust heats up as the car warms up, it could very well go away due to the metal expanding.
FCmaniac is offline   Reply With Quote
Old 10-19-2012, 08:45 PM   #24
pocketdrummer
Scooby Newbie
 
Member#: 197301
Join Date: Dec 2008
Chapter/Region: TXIC
Location: Austin, TX
Vehicle:
2005 WRX STI
W R Blue (02C)

Default

Quote:
Originally Posted by FCmaniac View Post
video 1 to me doesn't sound like rod knock... it sounds like t belt tensioner

video 2 sounds like up heatshield. My 04's had the same issue... replaced up and its gone. And when the exhaust heats up as the car warms up, it could very well go away due to the metal expanding.
But, why would it only make the noise when it's in gear?
pocketdrummer is offline   Reply With Quote
Old 10-25-2012, 04:14 PM   #25
pocketdrummer
Scooby Newbie
 
Member#: 197301
Join Date: Dec 2008
Chapter/Region: TXIC
Location: Austin, TX
Vehicle:
2005 WRX STI
W R Blue (02C)

Default

This just in!

My car threw a CEL today...

I took it to autozone (I don't have a scan tool), and it said Catalyst Efficiency below threshold - Bank 1. And the list of possible issues was bad cat, ignition system malfunction, or rich AFR.

Any thoughts?
pocketdrummer 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 04:22 AM.


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.