my 2000 frontier only has 70000 miles on it but in the past few months when you start it up there is a squeal which then stops, but even in idle if you give it gas it is a constant squeal. When in drive, as you accelerate it squeals very loudly but when you let up off the gas it stops, but as soon as you accelerate again the squeal comes back. Could this be a water pump or timing belt issue with a bearing going out.
Jack in Huntsville Al.
You may have a "slick" area on your belt and/or pulley. Try a little belt dressing on your contact points first, water pumps and timing belts wont make this noise. Idler pulleys may make this noise if the internal bearings are shot. You can view the main belt drive at idle and see if the pulley is walking or wobbles.