The tension of the 3.2L engine is set entirely by the pressure of the gas piston tensioner and is not adjustable. I assume you are talking about a 3.0L. A new belt may whine for several thousand miles. Are you sure it is the ting belt? The Goodyear "Gatorback" accessory belts on my car let out a noticeable whine. So much that I have considered replacing them just to quiet things down.
Yes, you can reset the tension of the timing belt and no, you don't have to remove any of the timing belt covers. Place a 19mm socket on the crankshaft damper bolt and rotate the engine clockwise until the first, yellow mark on the damper aligns with the "0" degree mark on the lower timing cover. This places the engine at 60 degrees before top dead center (BTDC) on the number one cylinder and puts the greatest tension on the front side of the timing belt. For information, the second, white mark on the damper aligned to the "0" mark is TDC on the #1 cylinder.
Now remove the 2" x 1.5" door off the lower timing belt cover. Place a flathead screwdriver under the single tab and twist. This exposes the 14mm nut on the tensioner pulley. Loosen the nut about a half turn to allow the spring to reset the tension to the proper level. Tighten the tensioner nut to 25-37 lb-ft and reinstall the plastic door.
NOTE: It is very important that the engine is rotated clockwise until the yellow mark is set to the "0" index before setting the timing belt tension.
