E90Post
 


E92-lighting
 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Powertrain and Drivetrain Discussions > NA Engine (non-turbo) / Drivetrain / Exhaust Modifications > P306 Misfire Code, Need new plugs? Coil?



Reply
 
Thread Tools Search this Thread
      04-03-2011, 05:15 PM   #1
bmwstylexx
Second Lieutenant
 
Drives: 2007 335i
Join Date: Jan 2011
Location: Charlotte NC

Posts: 224
iTrader: (10)

P306 Misfire Code, Need new plugs? Coil?

Took the car to Autozone and they scanned the CEL for me and showed P306 - engine misfire.. Said I might need new plugs and coil? But they didn't have the plugs I needed so I went to Advance and they said the coil was cyclinder specific and I would need to know which one I needed? So now I'm confused...

How do I know which coil I need replaced (of if i even need a coil replaced)? Car had a slow crank, now CEL is on and car "Shakes" when started.

Any help would be appreciated.
bmwstylexx is offline  
0
Reply With Quote
      04-03-2011, 05:29 PM   #2
arctic330i
Lieutenant Colonel
 
arctic330i's Avatar
 
Drives: 2013 335is
Join Date: Aug 2010
Location: Gainesville, Fl

Posts: 1,920
iTrader: (8)

Garage List
I had the same code, it was an ignition coil, it was about $250 at the dealer. I think the part was $70. I will DIY if it ever happens again for sure
__________________
See my full mod list in my garage
arctic330i is offline   United_States
0
Reply With Quote
      04-03-2011, 05:42 PM   #3
bmwstylexx
Second Lieutenant
 
Drives: 2007 335i
Join Date: Jan 2011
Location: Charlotte NC

Posts: 224
iTrader: (10)

Quote:
Originally Posted by arctic330i View Post
I had the same code, it was an ignition coil, it was about $250 at the dealer. I think the part was $70. I will DIY if it ever happens again for sure
That's what they thought it was as well... The code says "Misfire on Cyclinder 6"... Which cyclinder is 6? the first one at the front? or the last one at the back? (see pic) They said if i switch the coil from cyclinder 6 to cyclinder 5 and it was the cyclinder that was faulty.. the new code would now say "Misfire cyclinder 5.. instead of Misfire cyclinder 6"
Attached Images
 
bmwstylexx is offline  
0
Reply With Quote
      04-03-2011, 10:08 PM   #4
bmwstylexx
Second Lieutenant
 
Drives: 2007 335i
Join Date: Jan 2011
Location: Charlotte NC

Posts: 224
iTrader: (10)

anyone know which way the cyclinders are numbered????
bmwstylexx is offline  
0
Reply With Quote
      04-03-2011, 10:09 PM   #5
Got Euro ?
Here Comes The Boom
 
Got Euro ?'s Avatar
 
Drives: e92
Join Date: Feb 2011
Location: NNJ

Posts: 494
iTrader: (1)

No your cylinders arent in that order, have your car running and pull each coil out 1 by 1..Basically take the first one out and if it sounds like its gonna stall or losses power or sounds funny then you know the coil is working, put it back in and move onto the next coil.. When you pull the coil and no change is made , then that is the faulty coil.. Depending on how bad and how long you been riding your car like this, your plugs might be fouled from all the unburnt fuel but you should be ok with spark plugs. And it shouldnt matter which cylinder it is cuz all the coils do the same shit .. Just bring in the coil pack that is bad and tell them you need that part. Its not like your changing out your piston rings or checking compression ratio to know exactly which cylinder is what. GL
__________________
▀▄▀▄▀▄// DTMPOWER //
Got Euro ? is offline   United_States
0
Reply With Quote
      04-03-2011, 10:12 PM   #6
bmwstylexx
Second Lieutenant
 
Drives: 2007 335i
Join Date: Jan 2011
Location: Charlotte NC

Posts: 224
iTrader: (10)

Quote:
Originally Posted by Got Euro ? View Post
No your cylinders arent in that order, have your car running and pull each coil out 1 by 1..Basically take the first one out and if it sounds like its gonna stall or losses power or sounds funny then you know the coil is working, put it back in and move onto the next coil.. When you pull the coil and no change is made , then that is the faulty coil.. Depending on how bad and how long you been riding your car like this, your plugs might be fouled from all the unburnt fuel but you should be ok with spark plugs. And it shouldnt matter which cylinder it is cuz all the coils do the same shit .. Just bring in the coil pack that is bad and tell them you need that part.
If the car is already "shaking" and making a rough idle noise will this process work?
bmwstylexx is offline  
0
Reply With Quote
      04-03-2011, 10:15 PM   #7
Got Euro ?
Here Comes The Boom
 
Got Euro ?'s Avatar
 
Drives: e92
Join Date: Feb 2011
Location: NNJ

Posts: 494
iTrader: (1)

Yes....... Just go 1 by 1, trust me lol you will know which one is bad.
__________________
▀▄▀▄▀▄// DTMPOWER //
Got Euro ? is offline   United_States
0
Reply With Quote
      04-03-2011, 10:18 PM   #8
bmwstylexx
Second Lieutenant
 
Drives: 2007 335i
Join Date: Jan 2011
Location: Charlotte NC

Posts: 224
iTrader: (10)

Quote:
Originally Posted by Got Euro ? View Post
Yes....... Just go 1 by 1, trust me lol you will know which one is bad.
Alright. Thanks! Ill try this tomorrow.
bmwstylexx is offline  
0
Reply With Quote
      04-04-2011, 07:28 AM   #9
Dracon
BimmerPost Supporting Vendor

 
Drives: 2006 330i E90
Join Date: Apr 2009
Location: Nashville, TN

Posts: 904
iTrader: (14)

Quote:
Originally Posted by bmwstylexx View Post
That's what they thought it was as well... The code says "Misfire on Cyclinder 6"... Which cyclinder is 6? the first one at the front? or the last one at the back? (see pic) They said if i switch the coil from cyclinder 6 to cyclinder 5 and it was the cyclinder that was faulty.. the new code would now say "Misfire cyclinder 5.. instead of Misfire cyclinder 6"
The position of the coils is:

[Back] 6 - 5 - 4 - 3 - 2 -1 [Front]

It's most likely a bad coil, if you need to replace the coils, it's good to replace all 6 as if one fails, the others are probably right behind it. It's about $40 a coil from Tischer BMW, you can order your spark plugs from them too and swap out the plugs while you are at it.
Dracon is offline   United_States
0
Reply With Quote
      04-04-2011, 09:16 AM   #10
fdriller9
Banned
 
Drives: '06 AW 330xi
Join Date: Mar 2009
Location: North Jersey/Philly/NYC

Posts: 7,090
iTrader: (4)

Garage List
2006 330xi  [3.22]
You should find someone with an Autologic, BT tool, GT1 etc and pull the codes.....it will tell you which cylinder is misfiring.
fdriller9 is offline   United_States
0
Reply With Quote
      04-04-2011, 09:28 AM   #11
Dracon
BimmerPost Supporting Vendor

 
Drives: 2006 330i E90
Join Date: Apr 2009
Location: Nashville, TN

Posts: 904
iTrader: (14)

Quote:
Originally Posted by ********* View Post
You should find someone with an Autologic, BT tool, GT1 etc and pull the codes.....it will tell you which cylinder is misfiring.
For a misfire code, a standard OBDII scanner is fine. P306 is misfire in cylinder 6. Just needs to swap the coils of 5 and 6, clear the code, start up the car and see if a code comes up in cylinder 5 (should be P305), if so, bad coil. Replace dead coil, clear code, enjoy.
Dracon is offline   United_States
0
Reply With Quote
      04-04-2011, 10:09 PM   #12
bmwstylexx
Second Lieutenant
 
Drives: 2007 335i
Join Date: Jan 2011
Location: Charlotte NC

Posts: 224
iTrader: (10)

Quote:
Originally Posted by Dracon View Post
The position of the coils is:

[Back] 6 - 5 - 4 - 3 - 2 -1 [Front]

It's most likely a bad coil, if you need to replace the coils, it's good to replace all 6 as if one fails, the others are probably right behind it. It's about $40 a coil from Tischer BMW, you can order your spark plugs from them too and swap out the plugs while you are at it.
Thanks, I changed the plugs out today... was simple to do until I got to plug 6 and that one was a beast being way in the back..

I swapped the coils and had autozone rescan it and sure enough... showed misfire in a different cyclinder, this time cylinder 4. Ordered a replacement from them for $28.. will be here by 10 in the morning... I'm hoping this takes care of it.

Thanks for the info.. at least I know which one 4 is now!
bmwstylexx is offline  
0
Reply With Quote
      04-04-2011, 11:38 PM   #13
bmwdharma
Registered
 
Drives: 530xi grocery wagon
Join Date: Apr 2011
Location: canada

Posts: 4
iTrader: (0)

Garage List
I have a similar problem (P0303) and tried the swap solution on both the coil and the plugs, one at a time, of course. No joy however. The engine still runs like junk.

Does anybody know if the N52 engine has a timing belt or is it a chain? Right now my Volvo 240 engine runs smoother.........
bmwdharma is offline  
0
Reply With Quote
      04-05-2011, 01:31 AM   #14
Got Euro ?
Here Comes The Boom
 
Got Euro ?'s Avatar
 
Drives: e92
Join Date: Feb 2011
Location: NNJ

Posts: 494
iTrader: (1)

chain
__________________
▀▄▀▄▀▄// DTMPOWER //
Got Euro ? is offline   United_States
0
Reply With Quote
      04-05-2011, 07:07 AM   #15
bmwdharma
Registered
 
Drives: 530xi grocery wagon
Join Date: Apr 2011
Location: canada

Posts: 4
iTrader: (0)

Garage List
This may seem like speculation but is it possible for the cam shaft to slip out of sync by a tooth due to the VVT and not the chain? If so, how do I even check this? I have an OBD scanner but it doesn't show any code beyond the P0303.
bmwdharma is offline  
0
Reply With Quote
      04-05-2011, 07:52 AM   #16
micah_675
Second Lieutenant
 
Drives: 2006 325i (US Spec)
Join Date: Sep 2010
Location: Germany

Posts: 253
iTrader: (0)

you would throw a VANOS code if that happened. Jumping teeth is a much larger problem than misfiring. You do NOT have that issue. (it would happen on ALL cylinders if you jumped a tooth....)
micah_675 is offline  
0
Reply With Quote
      04-05-2011, 08:11 AM   #17
bmwdharma
Registered
 
Drives: 530xi grocery wagon
Join Date: Apr 2011
Location: canada

Posts: 4
iTrader: (0)

Garage List
Thanks for this. Perhaps you can suggest a possible fix? The problem occured after I stalled out climbing a hill. (Too slow & wrong gear) I had to jam on the brakes to stop from rolling backwards and do an on hill restart.

Currently, it starts fine but idles and runs rough and has the P0303 code, and lacks power due to running on 5 of 6 cylinders. I am loathe to drive it due to possible engine damage.

The issue seems to be beyond the plug and coil in my case but I am not sure how to proceed beyond checking the compression. I am a newbie to BMWs and am waiting for documentation on the engine.......
bmwdharma is offline  
0
Reply With Quote
      04-07-2011, 08:52 PM   #18
bmwstylexx
Second Lieutenant
 
Drives: 2007 335i
Join Date: Jan 2011
Location: Charlotte NC

Posts: 224
iTrader: (10)

Replaced the Coil.... Car runs fine now. Thanks for the info guys.
__________________
2007 335i. 6MT. m3 Steering wheel with alcantara, Black grill with brushed aluminum top, AC Schnitzer front lip, painted eyelids, AC Schnitzer pedals, AC Mats, Mtech rear spoiler, 4 inch Magnaflow Tips, AFE Dual Cone Intake, Jb+
bmwstylexx is offline  
0
Reply With Quote
      04-07-2011, 09:46 PM   #19
Dracon
BimmerPost Supporting Vendor

 
Drives: 2006 330i E90
Join Date: Apr 2009
Location: Nashville, TN

Posts: 904
iTrader: (14)

Quote:
Originally Posted by bmwstylexx View Post
Replaced the Coil.... Car runs fine now. Thanks for the info guys.
Might want to consider replacing the rest if you only replaced one. Once one dies, the others are usually right behind it.
Dracon is offline   United_States
0
Reply With Quote
      04-10-2011, 10:02 PM   #20
bmwstylexx
Second Lieutenant
 
Drives: 2007 335i
Join Date: Jan 2011
Location: Charlotte NC

Posts: 224
iTrader: (10)

Quote:
Originally Posted by Dracon View Post
Might want to consider replacing the rest if you only replaced one. Once one dies, the others are usually right behind it.
Car is off to Carmax to be sold.... so i just need it to run long enough to get there. lol
__________________
2007 335i. 6MT. m3 Steering wheel with alcantara, Black grill with brushed aluminum top, AC Schnitzer front lip, painted eyelids, AC Schnitzer pedals, AC Mats, Mtech rear spoiler, 4 inch Magnaflow Tips, AFE Dual Cone Intake, Jb+
bmwstylexx is offline  
0
Reply With Quote
      05-31-2012, 09:28 PM   #21
az002124
Registered
 
Drives: BMW 330Xi
Join Date: May 2012
Location: Salt Lake City

Posts: 1
iTrader: (0)

Engine coil Miss fire

It was the engine coil in cylinder #5. Got a new coil from O'riellys with life time warrenty.
az002124 is offline  
0
Reply With Quote
Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 -5. The time now is 05:33 AM.




e90post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST