Site Sponsors & Vendors
Results 1 to 5 of 5

Thread: p0306 code cylinder 6 misfire

  1. #1
    G8 driving Jarhead rclinton's Avatar
    Join Date
    Sep 2008
    Location
    Jacksonville, NC
    Posts
    104
    Post Thanks / Like

    Unhappy p0306 code cylinder 6 misfire

    Read all posts and surfed the internet for some help. Posted in an old thread but wanted to get visibility here. As the title stated driving home got the CEL and ESS lights. Car running rough. Swapped #4 and #6 coil pacs and wires. Puta. Ew plug in number six. P0306 code cleared but came back after a bit at above idle RPM. I have seen other post but no resolution. Hoping there is a fix out there somewhere. Thanks in advance for any insight
    2009 Pacific Slate Metallic G8 GT with hacked Atari gages. Pioneer F500BT GPS/Bluetooth. Mods: I can not confirm or deny the existence of modifications on this car.

  2. #2
    Member chevybernie's Avatar
    Join Date
    Aug 2017
    Location
    Germany, Bavaria, 100km near Munich
    Posts
    57
    Post Thanks / Like

    Default

    I had the same problem last year. After kickdown ,when i passed a truck, suddenly the engine light and ess came on. Engine stottered. With every litlle bit acceleration, the ess light came. I looked, take all plugs out and on 2 ignition cables have been a little white , - like powder outside. They had been near the headers. I changed the spark plugs and all ignition cables and all was ok. ( I hope, you understand. My english is not so good).

  3. #3
    G8 driving Jarhead rclinton's Avatar
    Join Date
    Sep 2008
    Location
    Jacksonville, NC
    Posts
    104
    Post Thanks / Like

    Default

    Quote Originally Posted by chevybernie View Post
    I had the same problem last year. After kickdown ,when i passed a truck, suddenly the engine light and ess came on. Engine stottered. With every litlle bit acceleration, the ess light came. I looked, take all plugs out and on 2 ignition cables have been a little white , - like powder outside. They had been near the headers. I changed the spark plugs and all ignition cables and all was ok. ( I hope, you understand. My english is not so good).

    English was great. Already bought the plugs and wires. Guess it’s time to roll up the sleeves and get a little dirty.
    2009 Pacific Slate Metallic G8 GT with hacked Atari gages. Pioneer F500BT GPS/Bluetooth. Mods: I can not confirm or deny the existence of modifications on this car.

  4. #4
    G8 driving Jarhead rclinton's Avatar
    Join Date
    Sep 2008
    Location
    Jacksonville, NC
    Posts
    104
    Post Thanks / Like

    Default

    Update. Changed all plugs and wires. Still got the P0306 code. Is the next step a leak down test?
    2009 Pacific Slate Metallic G8 GT with hacked Atari gages. Pioneer F500BT GPS/Bluetooth. Mods: I can not confirm or deny the existence of modifications on this car.

  5. #5
    Member
    Join Date
    Jul 2009
    Location
    Fort Worth, TX
    Posts
    88
    Post Thanks / Like

    Default

    Yes, you can do a leak down test and see what it says. Don't be that concerned if the leak down is 20% or less. If it's more than that figure out where its leaking from. I had the same issue on my LS3. I did the leak down test and it was greater than 40% on a couple of cylinders, and was leaking through the intake. I would also consider buying a remote camera before you do any removal of the heads or engine to see the inside of the cylinders. I did that with mine and saw some slight scoring on the cylinder walls.

    I ended up pulling the motor and found a lot of grey sludge in the bottom of the pan along with a chunk of metal. My heads and valves looked fine, the tops of the pistons look fine as well. I pulled the #8 piston out (it had the greatest amount of leak down) and it looks fine other than the coating on the piston skirt is wore off and the rings don't spin inside their grooves. Some very light scoring on the cylinder walls. 75k on my motor. Something on the inside was eating itself. I have not figured it out yet other than I need to rebuild my engine. I have delayed working on things until my career transition and finances are stable enough to spend money on go fast parts. Not sure how I am going to go with this project because it appears G8 specific parts are getting hard to source. No issues with mechanical bits since they stuck that LS3 in Camaros and Corvettes.
    69Project
    2009 G8 GXP
    Liquid Red 6M

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •