Welcome to the North American Subaru Impreza Owners Club Friday April 18, 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 2.5L 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 01-25-2010, 10:43 PM   #1
Aleksey
Scooby Specialist
 
Member#: 23445
Join Date: Aug 2002
Chapter/Region: MAIC
Location: NoVA
Vehicle:
2007 STI

Default CEL flashes under light load and goes away when load increases. No code.

Hey guys, I searched around, but couldn't find a similar issue. As the subject says, I get CEL flashing under light load. The problem isn't realted to speed - I see it sporatically in all gears. The CEL would flash until I give the engine more gas. Then it stops and everything is back to norm - no steady CEL. The car drives normally at this point, doesn't buck or make strange noises.

I have an OBD2 scanner from Autozone and it says that there is no codes.

Apart from this problem I'm having occasional misfire at cylinder 4 (P0304) and the car's idle is rough, even when the engine is warm. The misfire code shows up mostly when car idles too. I replaced all 4 spark plugs and so far it didn't change anything. I'm in the process of dealing with the misfire, but the blinking CEL puzzles me. What that could be and why there is no code left in the system when it happenes?

* Registered users of the site do not see these ads.

Last edited by Aleksey; 01-27-2010 at 01:43 PM.
Aleksey is offline   Reply With Quote
Old 01-25-2010, 11:21 PM   #2
sg_halvorsen
Scooby Specialist
 
Member#: 201924
Join Date: Feb 2009
Chapter/Region: MAIC
Location: State College, PA
Vehicle:
98 Forester with a
full wrx drivetrain swap

Default

Most likely the knock sensor. Do you have any engine management? (i.e. TSX UTEC) Utec is the most sensitive to sensing knock.

The light blinks when a knock/detonation is detected, the car retards timing a little to prevent detonation.

A list of any mods done to the car will help figure it out.
sg_halvorsen is offline   Reply With Quote
Old 01-25-2010, 11:30 PM   #3
Aleksey
Scooby Specialist
 
Member#: 23445
Join Date: Aug 2002
Chapter/Region: MAIC
Location: NoVA
Vehicle:
2007 STI

Default

I have AccessPort Stage 2 and a catted downpipe. The rest is stock.
Aleksey is offline   Reply With Quote
Old 01-26-2010, 10:01 AM   #4
ktmrider
Scooby Specialist
 
Member#: 125687
Join Date: Sep 2006
Chapter/Region: SWIC
Location: Albuquerque, NM
Vehicle:
2005 Legacy GT - 6MT
Black

Default

Check the "Pending Codes" if your scanner has this function. Flashing CEL, not solid, stores the code in Pending.
Likely it's the same P0304. Since you already did the plug(s) swap the coil with #2. Code stays then the injector is the possible culprit. Can't remember if the 07 has top or side feed, if side then swap with #2.
After all that and no change to the P0304 code worse news is bad piston or valve. Do a compression AND leakdown test. LD is gonna tell you more about rings and valve seal.
ktmrider is offline   Reply With Quote
Old 01-26-2010, 03:36 PM   #5
Aleksey
Scooby Specialist
 
Member#: 23445
Join Date: Aug 2002
Chapter/Region: MAIC
Location: NoVA
Vehicle:
2007 STI

Default

Will see if the pending codes are there and do plugs etc. Thank you.
Aleksey is offline   Reply With Quote
Old 01-27-2010, 01:26 PM   #6
Aleksey
Scooby Specialist
 
Member#: 23445
Join Date: Aug 2002
Chapter/Region: MAIC
Location: NoVA
Vehicle:
2007 STI

Default

so, at this point the idle is pretty rough, I smell gas from exhaust when it idles, 2nd and 4th cylinder misfire at low rpm. CEL flashes at low rpm and the car shakes roughly, but if I give it some gas it smoothens out and drives ok. So called a nearby Suby dealer to set an appointment and drop the car off to:

Check the wires and coils
Compression test
Leakdown test

I chose this route as the dealer gives a loaner car and I have no vacation time left = can't sit and wait there. But the appointment is on Wednesday next week (earliest they can have the loaner avail). Given the symptoms described, what am I risking driving the car ~30 miles every day? What is the chance that I'll damage the car even more by Wed provided that I baby it.

Last edited by Aleksey; 01-27-2010 at 01:50 PM.
Aleksey is offline   Reply With Quote
Old 01-30-2010, 03:40 AM   #7
Jimmy168
Scooby Newbie
 
Member#: 173614
Join Date: Mar 2008
Chapter/Region: SCIC
Location: California
Vehicle:
2007 STI
WRB

Default

there are many 06 and 07's having the misfire issue and replace the cam sensor works for most of my freind they acost about 90 in the subaru dealer and you just have to replace the on control cylinder four. hope it can work for you too buddy! Let me know^_^
Jimmy168 is offline   Reply With Quote
Old 01-30-2010, 11:47 AM   #8
sidewayz
Scooby Specialist
 
Member#: 5810
Join Date: Apr 2001
Chapter/Region: Tri-State
Location: Easton PA
Vehicle:
2001 S366 2.5RS

Default

Quote:
Originally Posted by Aleksey View Post
Apart from this problem I'm having occasional misfire at cylinder 4 (P0304) and the car's idle is rough, even when the engine is warm.

compression test... 100% dead #4 and possibly #2
sidewayz is online now   Reply With Quote
Old 02-01-2010, 12:16 PM   #9
Aleksey
Scooby Specialist
 
Member#: 23445
Join Date: Aug 2002
Chapter/Region: MAIC
Location: NoVA
Vehicle:
2007 STI

Default

Quote:
Originally Posted by sidewayz View Post
compression test... 100% dead #4 and possibly #2
that's what it is, #4 is dead - zero compression. I reeeally want to know what caused it.
Aleksey is offline   Reply With Quote
Old 02-01-2010, 12:28 PM   #10
sexyyrex
Scooby Specialist
 
Member#: 128022
Join Date: Oct 2006
Chapter/Region: Tri-State
Location: Danbury, CT
Vehicle:
2009 WRB STi
2007 Nissan Altima

Default

Quote:
Originally Posted by Aleksey View Post
that's what it is, #4 is dead - zero compression. I reeeally want to know what caused it.
From what i've read before, I believe its a fuel problem, coutersy of the subaru fuel system layout.

#4 is the last cylinder to get gas, casuing a lean condition and ends up eventually burning out the ring on #4. I've seen this a bunch of times and each time this was usually the generation concensus of the board.

Try upgrading the pressure regulator and/or fuel rails? I think that might have helped.

Hope this helps
sexyyrex is offline   Reply With Quote
Old 02-01-2010, 12:33 PM   #11
Aleksey
Scooby Specialist
 
Member#: 23445
Join Date: Aug 2002
Chapter/Region: MAIC
Location: NoVA
Vehicle:
2007 STI

Default

Would a better pump solve the problem? With this particular car I'd like to stay as stock as I can for financial reasons.
Aleksey is offline   Reply With Quote
Old 02-01-2010, 01:55 PM   #12
sidewayz
Scooby Specialist
 
Member#: 5810
Join Date: Apr 2001
Chapter/Region: Tri-State
Location: Easton PA
Vehicle:
2001 S366 2.5RS

Default

the pistons are junk. its not a fueling issue.. its a junk design for pistons :/
sidewayz is online now   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
Wheels squeak when I drive, goes away when I press brake nitr0x99 Brakes, Steering & Suspension 11 12-13-2010 12:34 AM
Unknown Squeal when NOT braking and goes away when lightly braked Gorge Brakes, Steering & Suspension 1 04-05-2008 02:57 AM
CEL Flashing P0301 Rough Idle and NO Power WRXerist Factory 2.0L Turbo Powertrain 26 02-05-2008 11:33 PM
weird sound but goes away when pushing the clutch x12oyx316x Transmission (AT/MT) & Driveline 23 06-22-2004 12:18 PM
Squeeky Rear Suspension when Cold, goes away when warm. nhalterman Brakes, Steering & Suspension 2 12-12-2001 03:31 PM


All times are GMT -4. The time now is 08:10 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.