Noise from fan area of 2005 Chevrolet Traillazer

Often hear a noise when driving and when let off of the gas I hear a rattling/spinning noise. Took to my mechanic and he put up on the lift with me inside and had me start engine and put in all wheel drive to replicate the noise. Isolated the noise to the fan area. Replaced the clutch fan but not the blades. Now when I start t-blazer in the morning, I hear a loud whirring noise until vehicle shifts up to third gear. Then when I let off gas I still hear original intermittent rattling/spinning noise. Looked in engine and I noticed that fan does have a wobble to it even though fan clutch is new. Called mechanic and he said it must be the fan blades. Since he replaced fan clutch and I still have the noise I want to be sure that the noise isn't something more sever. Also had leaking water pump replaced in 2012 when vehicle had 100,000 miles on it. Does this sound like the fan blades, or could it be something else like the water pump? When vehicle was on the lift they stood underneath and pinpointed noise to fan area and ruled out axles or drivetrain.