Manually creating Lambda expression to use as where predicate

I'm trying to use a lambda expression as a predicate for a call to IEnumerable.Where via reflection.

e.Query is of type System.Data.Objects.ObjectQuery<T> where T is known at Runtime. ObjectQuery implements IEnumerable.

//the current element type
Type currentType = e.Query.ElementType;

ParameterExpression typeParameterExpression = Expression.Parameter(currentType);
ConstantExpression propertyConstantExpression = Expression.Constant(GameId, GameId.GetType());
BinaryExpression equalityExpression = Expression.Equal(Expression.PropertyOrField(typeParameterExpression, "GameId"), propertyConstantExpression); 

Type genericFunc = typeof(Func<,>).MakeGenericType(currentType, typeof(bool)); //genericFunc = {Name = "Func`2" FullName = "System.Func`2[[OfferManagementBackOffice.Placement, OfferManagementBackOffice, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[System.Boolean, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]]"}
Expression predicateExpression = Expression.Lambda(genericFunc, equalityExpression, typeParameterExpression); //predicateExpression = {Param_0 => (Param_0.GameId == 2)}

var whereMethods = typeof(System.Linq.Enumerable)
.GetMethods(BindingFlags.Static | BindingFlags.Public)
.Where(mi => mi.Name == "Where");
MethodInfo whereMethod = null;
foreach (var methodInfo in whereMethods)
{
    var paramType = methodInfo.GetParameters()[1].ParameterType;
    if (paramType.GetGenericArguments().Count() == 2)
    {
        // we are looking for  Func<TSource, bool>, the other has 3
        whereMethod = methodInfo;
    }
}

whereMethod = whereMethod.MakeGenericMethod(currentType);
//whereMethod = {System.Collections.Generic.IEnumerable`1[OfferManagementBackOffice.Placement] Where[Placement](System.Collections.Generic.IEnumerable`1[OfferManagementBackOffice.Placement], System.Func`2[OfferManagementBackOffice.Placement,System.Boolean])}

var result = whereMethod.Invoke(e.Query, new object[] { e.Query, predicateExpression });

When I try the Invoke() on whereMethod I get this error:

Error: Object of type 'System.Linq.Expressions.Expression1[System.Func2[OfferManagementBackOffice.Placement,System.Boolean]]' cannot be converted to type 'System.Func`2[OfferManagementBackOffice.Placement,System.Boolean]'.

What I'm trying to achieve above is this (here T = Placement), but for any type.

Expression<Func<Placement, bool>> lambda1 = Expression.Lambda<Func<Placement, bool>>(equalityExpression, typeParameterExpression);
e.Query.Cast<Placement>().Where(lambda1);