Please Help!!Turbo whistle from under the hood?!?!?!?
About two days ago i parked my truck and left it idleing then all of the sudden i hear what sounded like a whistling sound from under the hood!?!? At idle is whistles the if i rev it up to abt 1000 rpm it goes away but as soon as it goes to idle it makes a whistle noise again!??! when driving down the road it makes no noise at all... it also happens if i am coasting down a hill. i get no smoke, no rough idle, no lose of performance!!! im not sure what this is... any info will help alot!!!!