If it is brown oil, it could be most likely coming from the oil cooler in the center of the engine valley. If it is reddish(could be brown also, depending on the condition), it could be coming from the transmission oil cooler that is in the radiator. The pressures in the coolers are typically more than cooling system pressure, and that could explain leaking in one direction, and not the other.
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Monday, October 31st, 2011 AT 3:49 PM