burnt exhaust valves in all 4 cylinders, and burnt cylinder wall in #3...
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This is a discussion on burnt exhaust valves in all 4 cylinders, and burnt cylinder wall in #3... within the General Maintenance, Troubleshooting & Accidents. forums, part of the Tech & Modifying & General Repairs category; SO.... I finally have found out the cause of my misfire issue... I had the dealer tear down the engine ...

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    Registered User 06scoobyrex's Avatar
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    burnt exhaust valves in all 4 cylinders, and burnt cylinder wall in #3...

    SO.... I finally have found out the cause of my misfire issue... I had the dealer tear down the engine and I have burnt exhaust valve seats in all cylinders and a scorched cylinder wall in #3... My only question is... What causes this to happen?
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    UnBanned Sinister's Avatar
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    Registered User 06scoobyrex's Avatar
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    Yeah it does suck, but I did buy it used... so... I look at it as a clean slate with the car and I will know the mechanical condition of the motor for now on...
    Hawk-Eye Alliance #801
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    The Fruit mangostick's Avatar
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    Quote Originally Posted by 06scoobyrex View Post
    SO.... I finally have found out the cause of my misfire issue... I had the dealer tear down the engine and I have burnt exhaust valve seats in all cylinders and a scorched cylinder wall in #3... My only question is... What causes this to happen?
    Cause? A lean run condition that went unchecked for a long time.

    I'd go to guess that it was probably a intake mod that was never tuned for, or.. above factory boost that wasn't tuned for.
    OBP 2010 5dr *traded*
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    Registered User 06scoobyrex's Avatar
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    Hmm... so where would the MBC be installed at so I can check and see if the previous owner tinkered with that?
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    Registered User EvoEatr's Avatar
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    Quote Originally Posted by mangostick View Post
    Cause? A lean run condition that went unchecked for a long time.

    I'd go to guess that it was probably a intake mod that was never tuned for, or.. above factory boost that wasn't tuned for.
    Bingo, Thats exactly what I was going to say haha

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    Registered User mudferret's Avatar
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    Damn, that sucks to hear. Any warranty left, or a used car warranty?
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    The Fruit mangostick's Avatar
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    Quote Originally Posted by EvoEatr View Post
    Bingo, Thats exactly what I was going to say haha
    hahaa.. I got a mean fast clickin finger

    @ scooby.. a mbc as in "manual boost controler" ? .. mmm nah man you would want to hook up a vac/boost gauge to make sure that you're not overboosting. A mbc works to reduce the amount of boost that reaches the wastegate so that it stays closed longer adding more boost. In regards to setting lower .. you cant go below the spring rating on your wastegate.

    You can check to see if the car has been tuned, any shop with a tractix cable or even the dealer can see if the unit has been re-flashed.

    Personally what I would do is after you get the hard parts set straight again go right to a good tuner and have them work you up a nice solid n safe tune. No sense in letting damage like that (and it takes a good while to really burn valves n cylinder walls) happen again.

    although, failure is always an excuse to upgrade if the wallet allows
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    Registered User 06scoobyrex's Avatar
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    Well.. In my last 3 months of heel trying to figure out what was wrong with it I have taken it to 2 different dealer ships and not including all the stuff I replaced/checked myself... I dicided to take it in and find out what's wrong with it... I called SOA and they had extended the powertrain warranty to 63K and it has 62,xxx on it and I do have an extended warranty as well, so I will find out tommarow if they will cover it... If not then it looks like I'm out 3+ thousand dollars...
    Hawk-Eye Alliance #801
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    Registered User 06scoobyrex's Avatar
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    I know what they do, but wasn't sure where it would've been hooked up at to see if the previous owner had 1 on it... I do have my car tuned by Anub1s and we did about 2 hours of datalogging and he fixed a boost osculation issue I had... he flashed it for me about 3 weeks after I had bought it... the map is really conservative and safe and still pulled hard and no issues were found... the only thing I noticed was a rough idle and a small backfire pop here and there...
    Hawk-Eye Alliance #801
    The Impreza "this was repaired/replaced at what mileage" database (Please Contribute)
    http://www.clubwrx.net/forums/showth...57#post2688257

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    The Fruit mangostick's Avatar
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    ah.. I see. Makes sense.

    Leaks in the intake tract after the maf sensor can also cause a lean run condition. How were the a/f Ratios when you were logging?
    OBP 2010 5dr *traded*
    SWP 2013 FRS
    My name is Shawn, I'm a Devout Practicalist and I'm addicted to flat4's
    This page has had 1,666 visits
    SUCH IS MANGO!

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