had orange gunk in the resivoir in my 2006 chevy cobalt flushed it out and replaced old resivior now its running at 230F?

6 Answers

  • 2 years ago

    Probably has some trapped air since the flushing. Alot of these newer cars have that issue.

  • 2 years ago

    This is probably a job for a professional. Dexcool has a reputation for producing really wicked sludge in some engines but not in others, and nobody seems to know why. GM and Texaco insist it is formed when the coolant level gets too low and air gets into the radiator but analysis of the sludge suggests the sludge contains rubber debris and stop-leak pellets as well. Your 2006 almost certainly has EPDM hoses, so rubber may not be a factor.

    Anyway, your observation in the surge tank suggests you have sludge in the system and ordinary flushes does not help it at all. There are complaints of flushing making it worse but I think those are just that the flush moves the sludge to worse spots. GM supposedly uses an acidic flush to clear the sludge.

    EDIT - the post by Anorak in the source has the full procedure for cleaning out Dexcool sludge. Expand his post to see the text of the TSB.

    To see how bad it can be, check out the video starting about 9:44


    Youtube thumbnail

  • JetDoc
    Lv 7
    2 years ago

    That's nice. Did you want to ask a question while you're here?

  • 2 years ago

    Is it just running at 230 degrees or is it over heating?

    The radiator electric fan should come on around 228 degrees.

    Replace the thermostat if you think it's running too hot.

    Source(s): Mitsubishi Master Tech
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  • Bill
    Lv 7
    2 years ago

    What temperature was it running at before? The orange gunk was probably antifreeze. Did you replace it with the recommended antifreeze?

  • Anonymous
    2 years ago

    Bleed the coolant. Pressure test the system for leaks. Replace the thermostat. Check for a clogged radiator. Check for a bad water pump.

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