97 lesbare whistle/squeal loud at start quiets down after warm up. checked all pulleys and belts not the problem. checked pcv possible problem not sure water pump might be too i lose coolant about every 6 months a small amount out of the over flow tank i have noticed

Welcome to AF, both o rings in place in the pcv/map sensor? Remove belts see if noise is gone #2.

bought the kit from gm for the pcv comes with new spring pcv and gaskets still have noise belts are next popped a p1406 also will look into that