Why does your 2004 Ford Escape Squeal when you accelerate?

Answer 1

Your Accessory Drive Belt may be slipping. This is often due to a wobbly pulley (water pump, air cond compressor, oil pump, alternator, Power Steering pump, idler pulley, tensioner pulley) or a weak Tensioner or a badly worn Drive Belt or any combination of the three!

This slip becomes obvious when you turn on the air conditioner (compressor clutch engages putting a load on the Drive Belt) or you start to accelerate from a complete stop or when going uphill. Usually when the engine is on a low gear and the momentum has not built up enough to overcome the load(s) that is placed on the Accessory Drive Belt.

My wife's 2006 Escape had a wobbly Idler Pulley, weak Belt Tensioner and worn Accessory Drive Belt (ribs become sharp or V-like, while new belt grooves are U-like and fat). When I replaced those three the squeal went away and because the belt was turning the accessories optimally (alternator especially) the engine was running with extra oomph! It was not a difficult job to do.