Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie
Please note that it is not permitted to have referral links posted in your signature. Keep these links contained in the appropriate forum. Thank you.

https://www.boards.ie/discussion/2055940817/signature-rules
Hi all,
Vanilla are planning an update to the site on April 24th (next Wednesday). It is a major PHP8 update which is expected to boost performance across the site. The site will be down from 7pm and it is expected to take about an hour to complete. We appreciate your patience during the update.
Thanks all.

Mazda 6 1.8 P0300

Options
  • 24-07-2014 10:05pm
    #1
    visual
    Closed Accounts Posts: 3,268 ✭✭✭


    Mazda 6 1.8 petrol 2003

    flashing amber engine warning light
    car feels like it is misfiring

    read the OBD and got fault code P0300

    any ideas what it most likely to be ?


Comments

  • Options
    #2
    Stella Virgo
    Banned (with Prison Access) Posts: 478 ✭✭Stella Virgo


    try reading this....https://www.google.ie/search?q=fault+code+P0300&ie=utf-8&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&channel=fflb&gws_rd=cr&ei=jHfRU8jlCfPN7Abv3ICQAw


  • Options
    #3
    advertsfox
    Registered Users Posts: 2,699 ✭✭✭advertsfox


    P0300 Mazda - Random Cylinder Misfire Detected - http://engine-codes.com/p0300_mazda.html

    The P0300 code means that a cylinder(s) is misfiring or is randomly misfiring. Start by checking for intake leaks, intake gaskets are common caused of multi-cylinder misfiring. If no leak are found the next step is to replace the spark plugs.

    Possible symptoms:

    - Engine Light ON (or Service Engine Soon Warning Light)
    - Lack/loss of power
    - Hard start
    - Engine hesitation

    Possible causes:

    - Faulty spark plug (s)
    - Faulty ignition coil (s)
    - Clogged or faulty fuel injector (s)
    - Intake air leak
    - Fuel injectors harness is open or shorted
    - Fuel Injectors circuit poor electrical connection
    - Ignition coils harness is open or shorted
    - Ignition coils circuit poor electrical connection
    - Insufficient cylinders compression
    - Incorrect fuel pressure

    http://engine-codes.com/p0300_mazda.html


  • Options
    #4
    visual
    Closed Accounts Posts: 3,268 ✭✭✭visual


    Had a chance to inspect a few things

    it appears a new coil pack was recently fitted so I pulled the plug leads one at a time.
    1 & 4 disconnected engine cuts out but 2 & 3 has little effect.

    Took out all the plugs 1 & 4 look normal 2 &3 black and fouled. plug 2 had a crack in insulation on body.

    I had a set of new plugs same size but not the one recommend for car so stuck these in to help diagnose fault of p0300 multiple misfires
    reset codes and short drive and have p0303 code 3rs cylinder misfiring. Leads seem ok but might replace these anyway.

    Update : fitted new leads today no change still not firing on cylinder 3

    Was thinking injector fault and still hadn't ruled out coilpack.

    Using a spare spark plug I tested spark at all plugs all seem fine as best I could tell.

    Disconnect fuel rail and all injectors

    Visually looked ok turned over engine and spray pattern looked same for all injectors.

    Put everthing back.

    Start engine still got P0303 fault
    disconnecting injector 3 or spark plug lead to 3 makes no difference.

    Disconnect injector or plug to any other cylinder and noticable change.

    Im thinking mechanical fault with cylinder 3
    Maybe valve or piston. Just gussing now


  • Options
    #5
    Admldj
    Registered Users Posts: 188 ✭✭Admldj


    I had a similar issue with my 6 turned out to be the piston ring was gone ended up having to replace the engine! hopefully thats not your problem op


  • Options
    #6
    visual
    Closed Accounts Posts: 3,268 ✭✭✭visual


    Admldj wrote: »
    I had a similar issue with my 6 turned out to be the piston ring was gone ended up having to replace the engine! hopefully thats not your problem op

    Just back from picking up a compression tester.
    Fingers crossed its not something too serious.

    Why engine replacement was it cheaper than getting rings and pistons done ?

    If you don't mind me asking what was cost of engine ?


  • Advertisement
  • Options
    #7
    visual
    Closed Accounts Posts: 3,268 ✭✭✭visual


    Competed compression test
    all cylinders read about 250 except cylinder 3 the suspect cylinder. It was reading about 30


    Wet test on cylinder 3 it increased to 50

    My interpretation is cylinder head or valve faulty


  • Options
    #8
    Admldj
    Registered Users Posts: 188 ✭✭Admldj


    One my mates is a mechanic and told me the engines in the mazda 6 and mondeo need to be constantly checked for oil, the previous owner of mine had obviously let it run low because it went after about three weeks of owning the car! I was able to pick up a low mileage 04 engine for €400 in a breakers in cork and fitted it with my mate over two days, hasn't missed a beat since with nearly thirty thousand miles put on it, i'm religious about oil checks since though, every week its checked!


  • Options
    #9
    visual
    Closed Accounts Posts: 3,268 ✭✭✭visual


    Will have to get some quotes from mechanics for repair / replacement


Advertisement