New Serpentine Belt Step 2 - Most pulleys, including the serpentine belt tensioner are supported by a sealed roller bearing, if this bearing fails it can cause a squeaking squealing noise. Learn more
Serpentine Belt Tensioner
Idler Pulley Step 4 - Oil is used to lubricate the internal workings of the engine to avoid damage, when the level of oil available drops to insufficient levels it can cause a squeaking noise. Learn more
Engine Oil Level Helpful Information Squeaking sounds are created when metal is contacting metal combined with a linear motion. Detection of a squeaking noise can be difficult, moving around the engine compartment at various levels can help find the origin of the noise.