If you have belt squeal. Have the dealer or your mechanic check the crankshaft dampner/pulley. Mine on my MarkVIII was squealing and I changed the belt, it still squealed so after a close inspection I noticed the belt was misaligned and that the pulley part of the dampner was about a 1/4 inch off center. I have a spare engine that donated the dampner and have had no further problem excepting noisy idler pulleys.