[trularin]

Gurgling is the response of the heat in the engine being transfered to the fluid. It expands and is forced to the expansion tank. Then as the engine cools, the fluid contracts and pulls residual fluid from the tank to fill the void created by the shrinking volume of coolant.

As long as no air is introduced and a small amount is kept in the tank, it is considered a sealed system and should reliably cool the engine for years.

Got the same setup. Works great!