06 STI Cylinder #4 Misfire

bboyjohn · 08-27-2011, 01:22 PM

Seems like cylinder #4 is pretty popular these days

. LOL, I kid. But on a more serious note, She just barely hit 100k miles on the odometer and now shes throwing a misfit: Cylinder #4 Misfire. In case I haven't already mentioned, she's an 06 STI Cobb Stage 2 OTS MAP (at stage 2 for 80k miles).

I was able to cure the previous misfire on cyl#4 code with a brand new set of spark plugs. It's only been like 1k or 2k mile SINCE than, and now the code has returned.

When changing the spark plugs I noticed there was a tiny bit of oil inside the TMIC. The oil was around the area where it would mount up to the throttle body. The amount of oil found would be equivalent to less than a tablespoon.

I've already done a couple of data logs. Cylinder #4 roughness looks like it's celebrating independence day every couple seconds. Especially at idle. When idling it feels as if all the motor mounts are just ready to snap.
I'm not exactly a tuner and on top of that it's my first time data logging as well. Hopefully someone with much better credentials can tell me what's going on here exactly. Will be greatly appreciated.

I was told if the culprit were to be the O-Rings, I could just run the motor, remove the oil cap and smoke would appear.

*Even though she's at stage 2. I recently swapped out the 3in CBE back to the stocker. For approximately 20k miles: It has been 3in down-pipe mated to the STOCK exhaust system on Cobb Stage 2 OTS Map.* <--- Just putting that out there; not knowing if it's relevant or not to the issue at hand.*

Will have the data log up this evening. It's work time.

Any inputs/advice would be greatly appreciated.
Thanks again,
John

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mackeymx · 08-27-2011, 02:44 PM

I HATE to say this, but I bet you have very little compression in cylinder 4. I just experienced the same exact situation you did on my 04, and turns out I only had 60 psi in cylinder 4. Now the motor is in the middle of being pulled. I hate to say it, but I'm sure you have the same exact situation. Sorry man.

Uncle Scotty · 08-27-2011, 03:12 PM

its blowed up

Joshwrx04 · 08-27-2011, 06:38 PM

about to do a leak down in my 05, leaning to believe i have the same sitsuation:/

never had a misfire, or white smoke out of the filler or exhaust.
but still have a bad feeling its going to be cracked land..

Mr. Black Man · 08-27-2011, 07:37 PM

Most likely it's done for. Same happened to me sadly, 'cept I had 0psi.. yes 0.. in cylinder #4. Cracked Ringland. All of the other cylinders were 140psi and perfectly fine.

FCmaniac · 08-27-2011, 08:00 PM

ringland... and sorry bro

bboyjohn · 08-27-2011, 08:45 PM

I have the data log uploaded to the computer, but not sure how I would get it up here in the thread. LOL I'm not proficient at using HTML as you can tell. When I open the file on my computer it uses "Free Opener".

Could I get a little assistance please.

Thanks again,
John

Uncle Scotty · 08-28-2011, 12:09 AM

Code:

use the code tags on the advanced page

#

CTSparky · 08-28-2011, 04:37 AM

Quote:

Originally Posted by bboyjohn

When changing the spark plugs I noticed there was a tiny bit of oil inside the TMIC. The oil was around the area where it would mount up to the throttle body. The amount of oil found would be equivalent to less than a tablespoon.

I was told if the culprit were to be the O-Rings, I could just run the motor, remove the oil cap and smoke would appear.

*Even though she's at stage 2. I recently swapped out the 3in CBE back to the stocker. For approximately 20k miles: It has been 3in down-pipe mated to the STOCK exhaust system on Cobb Stage 2 OTS Map.* <--- Just putting that out there; not knowing if it's relevant or not to the issue at hand.*

Any inputs/advice would be greatly appreciated.
Thanks again,
John

John,
I just recently got my STi and I have been doing a lot of reading on the forums, and I do not feel qualified to comment on your most important issue, but in case you are still curious I can comment on some of your other issues:

The oil in the top mount is from spirited driving. It can also happen over the course of time with normal driving. The oil gets there from the pcv and the crankcase vents venting to the air intake tract. This is emissions related, and all it does is reduce intercooler effeciency. This is what they make air/oil seperators for. To prevent this from occuring.

Also you should not have any problems with the change in the exhaust piping sizing.

Good luck on the diagnosis, and maybe it is now time to build up the motor.

Spenk · 08-28-2011, 11:58 AM

These engines are junk.

Cheese13 · 08-30-2011, 08:55 PM

Just finishing putting mine back together, had 30 psi in number 3. Had a hammered out exhaust valve, cost me about 900 to fix

20SilverSti05 · 08-31-2011, 10:45 AM

switch the coilpacks and put new sparkplugs in...if its still on #4 then get a compression test and if the cylinder is fine...then it could be the fuel injector

WRXt4cy · 08-31-2011, 10:58 AM

I would suggest doing these things in this order:

1. Check the compression on cylinder 4.

2. Swap coil packs as he said ^^. See if the misfire moves

3. Swap injectors from 2 to 4, again see if the misfire moves

I've seen several misfire issues that were caused by injectors being stuck open.

Take a look at the spark plug from that cylinder and see if it is coated in a unburnt fuel

daseca07 · 08-31-2011, 12:26 PM

man what is up with all these expensive horror stories. stock daily driven motors losing compression, modded motors losing compression

. im on my first wrx had it for 5 months daily driver its got 67k miles STOCK and this is making me nervous. sorry about your troubles man i hope you get it taken care of quickly

mackeymx · 08-31-2011, 01:44 PM

Like I said, mine also went. I got a cylinder #4 misfire just like you did, and had VERY little white smoke from the exhaust and oil fill cap. I then kept throwing EVAP codes, not sure why, but turned out cylinder 4 only had 60psi. The car has only been stage 2 for 20k, with a total of 74k on it.

bboyjohn · 02-02-2012, 02:55 AM

Sorry if this thread is past over due but I finally came around to doing the compression test. Unfortunately, by the time I had everything pulled apart the motor had already cooled off. Cold motor: Cylinders #1 through #3; 140psi. Cylinder #4; 25psi.

SpongeBobSquarePants · 02-02-2012, 07:50 AM

Man that sucks. Time for a built motor

ehiddenidentity01 · 02-02-2012, 11:08 AM

I'm suprised #4 went first it's normally #3

bboyjohn · 02-02-2012, 03:46 PM

Quote:

Originally Posted by mackeymx

Like I said, mine also went. I got a cylinder #4 misfire just like you did, and had VERY little white smoke from the exhaust and oil fill cap. I then kept throwing EVAP codes, not sure why, but turned out cylinder 4 only had 60psi. The car has only been stage 2 for 20k, with a total of 74k on it.

guess i should be a little bit more optimistic. She was at stage 2 for 80k

; gave her all that mileage within 3 years

HastySpartacus · 11-29-2012, 03:28 PM

I've got the same problem
......but im staged 2 145k LMAO! cylinder 4 misfire PFFF code, idle is shaking the car damn near apart.

I have a warranty tho :-D

I.honestly hope it lost compression in cylinder 4

DHRDAN · 11-29-2012, 06:23 PM

the rubber on the coil pack often goes bad..... make sure you aren't arching because of bad rubber.

DHRDAN · 11-29-2012, 06:24 PM

Quote:

Originally Posted by Spenk

These engines are junk.

I take issue with this.

Owners are bad.

08-28-2011, 12:09 AM	#8
Uncle Scotty NASIOC Supporter Member#: 16200 Join Date: Mar 2002 Vehicle: OK Houston we have an Uncle	Code: use the code tags on the advanced page #

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08-27-2011, 01:22 PM	#1
bboyjohn Scooby Specialist Member#: 131024 Join Date: Nov 2006 Chapter/Region: SCIC Location: Orange County Vehicle: 2006 Impreza WRX STI Crystal Metallic Gray	06 STI Cylinder #4 Misfire Seems like cylinder #4 is pretty popular these days . LOL, I kid. But on a more serious note, She just barely hit 100k miles on the odometer and now shes throwing a misfit: Cylinder #4 Misfire. In case I haven't already mentioned, she's an 06 STI Cobb Stage 2 OTS MAP (at stage 2 for 80k miles). I was able to cure the previous misfire on cyl#4 code with a brand new set of spark plugs. It's only been like 1k or 2k mile SINCE than, and now the code has returned. When changing the spark plugs I noticed there was a tiny bit of oil inside the TMIC. The oil was around the area where it would mount up to the throttle body. The amount of oil found would be equivalent to less than a tablespoon. I've already done a couple of data logs. Cylinder #4 roughness looks like it's celebrating independence day every couple seconds. Especially at idle. When idling it feels as if all the motor mounts are just ready to snap. I'm not exactly a tuner and on top of that it's my first time data logging as well. Hopefully someone with much better credentials can tell me what's going on here exactly. Will be greatly appreciated. I was told if the culprit were to be the O-Rings, I could just run the motor, remove the oil cap and smoke would appear. Even though she's at stage 2. I recently swapped out the 3in CBE back to the stocker. For approximately 20k miles: It has been 3in down-pipe mated to the STOCK exhaust system on Cobb Stage 2 OTS Map. <--- Just putting that out there; not knowing if it's relevant or not to the issue at hand.* Will have the data log up this evening. It's work time. Any inputs/advice would be greatly appreciated. Thanks again, John * Registered users of the site do not see these ads.

08-27-2011, 02:44 PM	#2
mackeymx Scooby Newbie Member#: 258525 Join Date: Sep 2010 Chapter/Region: Tri-State Location: Poughkeepsie NY Vehicle: 2004 STi-BW7670 R6-Red/White	I HATE to say this, but I bet you have very little compression in cylinder 4. I just experienced the same exact situation you did on my 04, and turns out I only had 60 psi in cylinder 4. Now the motor is in the middle of being pulled. I hate to say it, but I'm sure you have the same exact situation. Sorry man.

08-27-2011, 03:12 PM	#3
Uncle Scotty NASIOC Supporter Member#: 16200 Join Date: Mar 2002 Vehicle: OK Houston we have an Uncle	its blowed up

08-27-2011, 06:38 PM	#4
Joshwrx04 Scooby Specialist Member#: 135429 Join Date: Dec 2006 Chapter/Region: NWIC Location: Lake Stevens WA Vehicle: '05 CGM STi '82 s-10 (427'nd soon)	about to do a leak down in my 05, leaning to believe i have the same sitsuation:/ never had a misfire, or white smoke out of the filler or exhaust. but still have a bad feeling its going to be cracked land..

08-27-2011, 07:37 PM	#5
Mr. Black Man Scooby Newbie Member#: 253148 Join Date: Jul 2010 Chapter/Region: TXIC Location: Houston, Texas Vehicle: 2006 Subaru STI WRB	Most likely it's done for. Same happened to me sadly, 'cept I had 0psi.. yes 0.. in cylinder #4. Cracked Ringland. All of the other cylinders were 140psi and perfectly fine.

08-27-2011, 08:00 PM	#6
FCmaniac Scooby Specialist Member#: 142029 Join Date: Feb 2007 Chapter/Region: Tri-State Location: Lehigh Valley, PA Vehicle: 2013 Fozz 2004 STi, 1991 Miata BRG	ringland... and sorry bro

08-27-2011, 08:45 PM	#7
bboyjohn Scooby Specialist Member#: 131024 Join Date: Nov 2006 Chapter/Region: SCIC Location: Orange County Vehicle: 2006 Impreza WRX STI Crystal Metallic Gray	I have the data log uploaded to the computer, but not sure how I would get it up here in the thread. LOL I'm not proficient at using HTML as you can tell. When I open the file on my computer it uses "Free Opener". Could I get a little assistance please. Thanks again, John

08-28-2011, 11:58 AM	#10
Spenk Scooby Guru Member#: 7164 Join Date: Jun 2001 Location: A World Of Noise Vehicle: ---> Spoiler alert: Everyone dies at the end.	These engines are junk.

08-30-2011, 08:55 PM	#11
Cheese13 Scooby Specialist Member#: 272366 Join Date: Jan 2011 Chapter/Region: MAIC Location: va beach Vehicle: 2003 Evo 8 gsr Bby	Just finishing putting mine back together, had 30 psi in number 3. Had a hammered out exhaust valve, cost me about 900 to fix

08-31-2011, 10:45 AM	#12
20SilverSti05 Scooby Newbie Member#: 188916 Join Date: Sep 2008 Chapter/Region: Tri-State Location: Medford NY Vehicle: 2005 WRX STI Silver	switch the coilpacks and put new sparkplugs in...if its still on #4 then get a compression test and if the cylinder is fine...then it could be the fuel injector

08-31-2011, 10:58 AM	#13
WRXt4cy Scooby Specialist Member#: 172698 Join Date: Feb 2008 Chapter/Region: MWSOC Location: Des Moines, IA Vehicle: 11 STi Stg2 E85 02 v8 Spec C E85	I would suggest doing these things in this order: 1. Check the compression on cylinder 4. 2. Swap coil packs as he said ^^. See if the misfire moves 3. Swap injectors from 2 to 4, again see if the misfire moves I've seen several misfire issues that were caused by injectors being stuck open. Take a look at the spark plug from that cylinder and see if it is coated in a unburnt fuel

08-31-2011, 12:26 PM	#14
daseca07 Scooby Newbie Member#: 277630 Join Date: Mar 2011 Chapter/Region: MAIC Location: Wheaton MD Vehicle: 2007 WRX TR WRB	man what is up with all these expensive horror stories. stock daily driven motors losing compression, modded motors losing compression . im on my first wrx had it for 5 months daily driver its got 67k miles STOCK and this is making me nervous. sorry about your troubles man i hope you get it taken care of quickly

08-31-2011, 01:44 PM	#15
mackeymx Scooby Newbie Member#: 258525 Join Date: Sep 2010 Chapter/Region: Tri-State Location: Poughkeepsie NY Vehicle: 2004 STi-BW7670 R6-Red/White	Like I said, mine also went. I got a cylinder #4 misfire just like you did, and had VERY little white smoke from the exhaust and oil fill cap. I then kept throwing EVAP codes, not sure why, but turned out cylinder 4 only had 60psi. The car has only been stage 2 for 20k, with a total of 74k on it.

02-02-2012, 02:55 AM	#16
bboyjohn Scooby Specialist Member#: 131024 Join Date: Nov 2006 Chapter/Region: SCIC Location: Orange County Vehicle: 2006 Impreza WRX STI Crystal Metallic Gray	Sorry if this thread is past over due but I finally came around to doing the compression test. Unfortunately, by the time I had everything pulled apart the motor had already cooled off. Cold motor: Cylinders #1 through #3; 140psi. Cylinder #4; 25psi.

02-02-2012, 07:50 AM	#17
SpongeBobSquarePants Scooby Newbie Member#: 296048 Join Date: Sep 2011 Chapter/Region: Tri-State Location: Bikini Bottom, NJ Vehicle: 2011 STI Blurple	Man that sucks. Time for a built motor

02-02-2012, 11:08 AM	#18
ehiddenidentity01 Scooby Newbie Member#: 279169 Join Date: Apr 2011 Location: marysville oh Vehicle: 2004 impreza wrx sti wrb	I'm suprised #4 went first it's normally #3

11-29-2012, 03:28 PM	#20
HastySpartacus Scooby Newbie Member#: 311032 Join Date: Feb 2012 Location: Bloomfield, CT	I've got the same problem ......but im staged 2 145k LMAO! cylinder 4 misfire PFFF code, idle is shaking the car damn near apart. I have a warranty tho :-D I.honestly hope it lost compression in cylinder 4

11-29-2012, 06:23 PM	#21
DHRDAN Scooby Specialist Member#: 204358 Join Date: Feb 2009 Chapter/Region: SCIC Location: Santa Paula, CA. Vehicle: 01 2.5RS W/ EJ257 Black	the rubber on the coil pack often goes bad..... make sure you aren't arching because of bad rubber.