After I start my engine I put it in drive give it gas and at that moment I get a hydraulic pulse sound (whirring) either from transmission or engine.

It only does it for a second then it is gone. After that it will only do it after I shut engine off for about 30 minutes restart put in drive then after I hit gas to go forward or reverse the whirring sound occurs again. Would the valve body make this sound???

This happens with cold or warm temp engine..

2003 preruner 2.7 automatic w/ OD