Camry?

I have a 2005 Camry, and have the same problem as yours. I have took to the dealer to have it checked. The dealer said that there is an air pocket inside the water cooling system, and fixed the problem by getting rid of this air pocket. After a while (one-month), it seems that the noise comes back again. I took this car to the dealer again three days ago, and yesterday, you called me and told that they can not fix this problem, and need contact Toyota Tech support about it.

If your car is still under warranty, take the car to the dealer as soon as possible. Let us know what is the result.