I have a 1991 420 sel with 217k is using water?.No water in engine.No puddles? on 1991 Mercedes-Benz 420SEL

Car has no water in engine, no puddles, but can see stream from under air breather. Doesn't go above 80 make on temp. gauge. but reserve light comes on and have to add water after driving about 20 mins.

Asked by for the 1991 Mercedes-Benz 420SEL
Hi my name is Jonathan from Mercedes Benz of Ft Lauderdale. It sounds like it could have a bad gasket. If you would like to bring it in, I would be happy to check it out and see whats going on with it for you. I can be reached at 954-713-1049. Thanks