My 2001 f-150 is making a humming noise when the engine is on idling on park. its a 4.6 v8. It makes this humming noise about once every 5 seconds. And when on highway when i try to pass or accelerate when the passing gear enters the engine makes a high screeching sound.. the belt is new and alternator also..
Country: United StatesMake: FordModel: F150 XLTYear: 2001Engine: 4.6
Hello, I'm Chris.I will do my best to answer your question fast and accurate using the info you have provided. Thanks for visiting Just Answer.
When its idling in park making noise, if you open the hood can you pinpoint the origin of the noise?
Does it seem to be coming from near the throttle body or a belt driven accessory?
It seems to be coming from a belt accessory.. now i can hear that noise while the truck is moving, like before i get to and leave a stop sign
You need to remove the belt, and clean it and all the pulleys with brake cleaner, now spin each pulley by hand, the ones that freewheel and wobble them. This will check there bearings. Especially the tensioner and idler pulleys. If all are good then reinstall and check the alignment of the belt and see if any pulleys are misaligned from mount issues.
16 years experience with Ford.