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coolant sludge??

Discussion in 'A4/S4 forum(B5 Chassis)' started by olds_kool, Apr 8, 2010.

  1. olds_kool
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    olds_kool Active Member

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    bought another cheap a4 1.8t, dodgy bodywork and oil light flashing after about 1/2 hours driving
    following byzans thread from a few weeks ago i managed to change oil pump (hardest part was cleaning sump out!)

    anyway when i pulled off top radiator hose a brown sludge came out (looked exactly like very thick chocolate milkshake)
    anyone got a clue what it is or what caused it?
    #1
  2. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator

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    Mixing standard antifreeze and original G12 coolant is the usual cause. G12+ is supposed to handle mixing better.

    You'll need to properly flush the whole system and refill with proper red OAT coolant.
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  3. Matt82
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    Matt82 Active Member

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    thats what i thought too
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  4. olds_kool
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    olds_kool Active Member

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    thats what i was hoping it was, had head gasket failure going through my mind though
    will get the hose on it and cross my fingers
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  5. Geeman
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    Geeman Low Life

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    If it's brown sludge, it'll be the coolant mix scenario. Nothing too much to worry about and recoverable from.

    You should worry if it's a light cream colour, like mayo. That's a sign of the head-gasket not being happy.
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  6. gavinsky23
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    gavinsky23 New Member

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    I had this and thought head gasket. Once I looked into it it was the oil cooler. Apparently it's much more common on these. It was only around £30 from euro car parts and an easy change, worst part is flushing the coolant system out. It happened after changing my oil pump, I think the increased pressure from the new pump prob caused it.
    #6

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