Ideas about Misfire on #3

Here's the story, I have a 2004 WRX and I did an UP and DP install. Had plenty of problems, took in into Nathan (wrxboy2003) and the exhaust part of the car is now corrected.

Nathan put the computer on it and got a misfire cylinder 3 code. He looked and saw that the coil pack was missing the bolt that holds it onto the block. He got a bolt to work and said it ran rough but better, then it started throwing the code again.

But during the initial install we removed the bolt that holds the little O2 sensor wire bracket. I am wondering if this bolt is the same bolt that holds the #3 cylider coil pack onto the block?

My next step to getting this thing fixed is to figure out this misfire. I am going to try and change the plugs and see if that helps the situation at all. The next logical step in my mind would be to replace the coil pack on that cylinder.

Anybody know what might be going on? I am wondering if the coil pack might have gotten damaged while it wasn't hooked up correctly. Or if the Spark plug is just good and fouled up. I am still pretty noob to a lot of the Subaru mechanicals, so anyone with advice i am willing to listen. good advice preferably.

Thanks,

Shaun

 

That's the same bolt

Also, try swapping coilpack 3 to 1 and 1 to 3, see how that goes

 

whats the year make and model

 

I thought it was the same bolt. Another issue when you are trying to put a car back together at 4 in the morning. Should have went to bed, and finished the next day. Dammit now i feel stupider

 

2004 WRX (added to first post)

 

definetely check the spark plug like you said. Theres probably a pretty good chance that it fried the coil when it wasn't attached fully. It probably wasnt getting a good connection on the spark plug and just arcing straight to the block. The different resistance may have damaged the coil. Check for any white spots or the boot being melted when you pull it out. No matter what do what NUKE said. If it still misfires, which it should, if the coil is bad the misfire will move to cyl 1. If the misfire doesn't move you have another problem. Let us know what you find.

 

Do you have easy acess to a scan tool or code reader to check the misfire code.

 

Depends if Nathan lets me keep it at his shop or if i just get it home and do some parking lot maintenance.

I dont want to be bugging nathan with my problems

 

Most auto parts stores will check your codes for you. Ex: Checker, Autozone, Bumper to Bumper. Where in the cities are you?

 

Eden Prairie

 

my guess is gonna be burned valve.....but thats just me

 

Checker Auto on flying cloud dr and regional ctr dr will pull your codes for free their number is 9529418090. P0300=random/multiple misfire P0301=cyl 1 misfire P0302=cyl 2 misfire P0303=cyl 3 misfire P 304=cyl 4 misfire

 

hopefully that'll help

 

p0303.. misfire cylinder 3.... I already pulled the code as he already stated in first post...

I forgot to pull the plug in my desire to find a bolt that worked and tightened down... there was NO visible damage to the coil boot... but as I told Sapalas it may have a damaged coil.. hopefully not the valve like imprezal says... that would suck...

And you can keep it at my shop till you can get it or whenever works for you... it is in the empty bay with Mike Wagners wagon.... my shop is turning into my dream garage.. slowly.. ha ha

Tomorrow I will find some time to pull that apart again, and swap those coils around.. I will also pull that plug for ya... unless you are free and wanna come play with it... you are welcome to come down...

 

hey bro, i got a reader too if you need it

 

Misfires are so common on Subaru's. Try changing the plugs and reset the ecu.

 

I know I was trying to help him out if he was going to diagnose himself with the switching of the coils

 

well Shaun, plugs are changed, I even swapped the coils on #3 & #1 around - NO difference... check engine is flashing, it hasnt stored a new code yet.. but it runs really rough at idle...

SO this is where I bow out as I am not an engine guy so much....

 

Well This Sux Anybody else have any ideas? I am out of ideas and want to get my car back.

When you swapped the coils did it read any code, as in still read #3 misfire or changed to #1 misfire?

 

leakdown test!

 

chip off the ol' valve is what it sounds like. I agree with eric, compression test then leakdown.

 

flashing cel = no good

 

What could have caused part of the valve to break off. I guess i don't see how a bad spark could have anything to do with the valve. Unless its a whole different problem that happen to occur at the same time.

 

I found this, so maybe i will get a new coil pack and at least try this.

http://forums.nasioc.com/forums/showthread.php?t=484369

 

A leak down test is a good idea. Another other semi-easy test you can do to eliminate the injectors from the equation is swap the #3 injector with the #1 injector. If the problem moves to #1 then its a bad injector. I would say its worth a try before pulling the motor out.

P.S. a flashing CEL means an engine damaging misfire is occuring so I definetely wouldn't run it too much like that.

 

Problem Solved

Problem was the #3 coil pack. Runs smooth now.

I am relieved that this was the problem not any valve or such.

Happy I found that post on nabisco (most randomly).

 

yep.. smooth as butter once I installed the NEW coil... and I also cleared the engine light too...

good thing I dont drink anymore or you would have been buying shares in a beer company.. ha ha ha

 

ha ha... yeah I am very happy for him... hate to see people spend money on a car for simple mods then find out the cars engine is junk... thank God it was just the coil.. DUE to being unplugged from spark plug and driven / run.... fried coil