Truck makes screeching noise every time I accelerate

Hi,

If it seems like a belt and you've replaced the tensioner and belt, I suspect it is likely related to one of the belt-driven accessories locking up or placing a heavier load on the belts than usual. Did you replace the alternator and power steering pump? I noticed you mentioned that.

Now, are you certain that the water pump isn't locking up or dragging? Is there any coolant or oil getting onto the belt? One other thing, does it do it regardless if the engine is cold or hot? I ask because about 3 months ago, I had a crazy experience with an exhaust manifold that when the engine was quick throttled, it sounded like a squeal. However, it went away when the engine warmed up to normal temperature.

I attached a pic below. Can you confirm if this is the correct belt routing for your vehicle? Also, have you checked to make sure the idler pulley is not bad? Also, does it only happen when the A/C or defroster is on which could indicate the A/C compressor could be an issue.

Let me know.

Joe