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Thread: SC Head Gasket Failure

  1. #1
    Join Date
    Jan 2005
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    18

    SC Head Gasket Failure

    When I got my 1990 Thunderbird SC 12 years ago it had only 21,000 miles. Now later with years of easy driving it now has 80,000 miles. My question is that I hear around 75K the head gasket fails. Is it inevitable that mine will fail soon, since it has never been replaced.

  2. #2
    Join Date
    May 2013
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    98
    From what I've read on this forum and in my own experience, chances are that you'll have to replace them at around 100k....if you make it that far. But that doesn't mean your car isn't the exception and will make it beyond that mark. Just my opinion...

  3. #3
    Join Date
    Dec 2007
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    Salem, OR
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    The answer to that question may depend more on how well maintained it is, what level of sanity is applied to any mods, and if you beat on it like a rented mule.

    Are there hints something is wrong? Do you have any other reasons to tear down the top end? Are you planning on certain mods?

  4. #4
    Join Date
    Jan 2005
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    18

    Head Gasket Failure

    Quote Originally Posted by KMT View Post
    The answer to that question may depend more on how well maintained it is, what level of sanity is applied to any mods, and if you beat on it like a rented mule.

    Are there hints something is wrong? Do you have any other reasons to tear down the top end? Are you planning on certain mods?
    Car has always run perfect and has never been abused. I guess at 80K I can expect to replace head gaskets soon regardless how gentle I drive. Thanks

  5. #5
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    Dec 2007
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    Quote Originally Posted by aspedt2 View Post
    Car has always run perfect and has never been abused. I guess at 80K I can expect to replace head gaskets soon regardless how gentle I drive. Thanks
    I'd guess if they haven't gone by now, you've got at the least a few more years at the rate you've been accruing miles. I'd not assume it's a given they will need attention any time soon.

  6. #6
    Join Date
    Sep 2012
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    Raleigh, North Carolina
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    590
    My original head gaskets lasted until 136,000 plus. your mileage may vary.
    Any idiot can make a Mustang fast...
    It takes a special idiot to make a Thunderbird fast!!!
    89 SC 4.3 stroker 384rwhp 473ftlbs
    Best ET 13.085 Best MPH 106.6... got some work to do!
    2016 V6 M90 Dyno Champ 2016 Mod 1 Runner Up

  7. #7
    Join Date
    May 2012
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    Oregon
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    I think head gasket survival has much to do with the operating quality and efficiency of the cooling system and how hard you drive the car. The only HG I've had fail was on my N/A 3.8 93 LX that I beat up as a kid. I flushed the cooling system without paying any attention to the fill/purge bolt on the top of the engine. A day or two later the HG popped. Pretty sure I had an air bubble in the loop because I didn't service the cooling system correctly.

  8. #8
    Join Date
    Feb 2003
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    Tinton Falls, NJ
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    I've personally replaced blown head gaskets on SCs anywhere from 120K to 175K. I also had an 89 XR7, with a late model blower and 10% pulley that I regularly beat the snot out of for almost 2 years, and at 168K, it spun a rod bearing, but the head gaskets never failed on that car. So in short, at only 80K, you are probably Ok for a while.

  9. #9
    Join Date
    Jul 2007
    Location
    South IL
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    yes, with this engine your head gasket will fail. when is the true question. after about 80k your at risk. some have lasted longer than 200k. mine took a poop at about 180k. its not if its when. when mine went it did give some warning. for about a month before it started losing coolant but i couldnt find any leaks. it wasnt blowing any smoke but it was somehow burning it off. then while driving at 0400, 70mph on the interstate on my way to report for duty it popped. still ran fine but noticed the temp gauge shoot up. as i started to pull over the engine then died and it was done.

  10. #10
    Join Date
    Sep 2014
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    Broken Arrow, Ok
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    The 2 SC's I have had in the past both blew at 150k. Both within a few thousand miles of each other.

  11. #11
    Join Date
    Feb 2014
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    840
    Quote Originally Posted by potshotscott View Post
    I think head gasket survival has much to do with the operating quality and efficiency of the cooling system and how hard you drive the car. The only HG I've had fail was on my N/A 3.8 93 LX that I beat up as a kid. I flushed the cooling system without paying any attention to the fill/purge bolt on the top of the engine. A day or two later the HG popped. Pretty sure I had an air bubble in the loop because I didn't service the cooling system correctly.
    You're right about cooling system efficiency, I think. Plus, I wonder sometimes, how many times someone may have put in regular fuel instead of premium (before we had bought our cars), and how frequently they changed the coolant.

  12. #12
    Join Date
    Apr 2002
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    Mine lasted 20 years and ~250k + miles...that was 7 years ago now, bottom end is still strong, I still use 1/2 qt oil every 3k like i did prior.

    No complaints at all

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