I recently had the following replaced on my car: timing belt, p/s belt, serpentine belt, camshaft and crank seals, timing belt idlers & tensioners, heater hoses, radiator hoses, and water pump. Now when I drive my car I hear a whirring noise at low RPM (circa 1800-2000 RPM). The independent shop where I had the work done thinks the noise is do to poor insulation in the timing belt cover. Is this accurate? I don't remember a noise when the dealership replaced the belts 60K miles ago--but just the three belts were replaced, nothing else.