I owe two ford explorer's one is a 01' model and the other is a 05' model, both have the 4.0 motors. Not two long ago the belt on the 05' started to make some squalling noise. So being a little knowledgeable about car's. I bought a new serpentine belt & replaced it.The new bet did quiet it own some but did not get rid of the noise.So the next step was to call a friend of mine that works for ford (In the service dept.)and ask him what he thought.He told me that the Harmonic Balancer pulley was defective.He began to... read full review »