I have heard that the water, even though it's bad for the exhaust(rust). It is a sign that your engine is in good condition. My .02
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1997 F150 XLT 4.6L Auto 4x4 ORP SC 3.55LS Oxford white, Med. Graphite Int. Bed Cap,Superchip,AirRaid,Bug Deflector. 3" Flowmaster 40 series,Bassani Nascar Tip.