No, 3 Liters is just fine...but consider that a wise top limit unless you're in marathon training...in the Sahara!
Water won't help you shed pounds but it removes wastes products and people who are on high protein diets and thus burning protein for fuel need to have the nitrogenous wastes diluted. THose ammonia type wastes are VERY hard on the kidneys.
Too much water can remove too much sodium, potassium and magnesium from our bodies and result in a dangerous state...brain swelling/delirium/disorientation kind of think.
Drink ENOUGH and a little more but don't force too much...you really won't lose any faster.