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coolant sludge??

olds_kool Apr 8, 2010

  1. olds_kool

    olds_kool Active Member VCDS Map User

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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?
     
  2. aragorn

    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

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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.
     
  3. Matt82

    Matt82 Active Member

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    thats what i thought too
     
  4. olds_kool

    olds_kool Active Member VCDS Map User

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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
     
  5. Geeman

    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.
     
  6. gavinsky23

    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.
     

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