mine just started squealing tonight. it did the same thing (squealing when I let off the gas no matter what my speed is). the noise is pretty loud when my window is down. My water pump was replaced in dec. 2011 and I never had this squeal before it broke so I am not sure if this is a water pump related squeal like the other poster pointed out and since the water pump is electric then why does it only squeal when you let off the gas while moving. I will try to check on it tomorrow using DIS.