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1999 BMW 323is Question: red oily substance in expansion tank



kristae, Longview, TX, February 16, 2011, 16:40

What would cause a reddish oily looking substance in my expansion tank along with coolant level being extremely high?

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  • Answer #1

    February 16, 2011, 16:48

    It sounds as if you have transmission fluid mixed in with your coolant. If the internal transmission cooler (usually built in with the radiator) has sprung a leak, its pumping transmission fluid into the radiator and mixing with the coolant.

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  • Reply

    kristae, February 16, 2011, 17:27

    I'm sorry if you've gotten this more than once. My computer is acting up. Is it safe to drive my car with this leak and trans. fluid in my coolant? I have a 2.5 hour drive home.

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