2006 mariner 3.0 motor now makes a very loud squeal when its put in any gear started as my wife had to take off fast so she would not get readended all belts are fine and only does it under load (In gear) I don't know what it could be.
Double check the water pump belt. They have been know to have bad pulley on the Escape/Mariner/Tribute models. Ive seen where the belt looks fine but the pulley is on its last legs.
