convertible top issues

[bennybimmer]

07 BMW z4 3.0i roadster convertible top was not operating....BMW dealer replaced the motor and it was working fine for 1 day then when I hit the button for the top to go down the motor makes a low whirling noise but the top does not go down right away. I have to hold the button down for about 30 to 40 seconds then the low whirling noise of the motor becomes a louder noise and at that point the top goes down.......anyone have same issues...