My 05 F150 seems to have developed a nasty engine noise. Its like a whine and seems to get worse the faster I go but its also there when the vehicle is idle. I have checked the oil (synthetic) thats good, I also wanted to check the transmission oil but it can only be checked when hot & I don't want to drive it more than necessary. The transmission oil however did look a healthy red. The guages all look ok when it being driven no low or high readings. I know its a difficult question but any ideas would be greatly appreciated

 

Check the condition of the serpentine belt. When they dry out they can give a whine like sound. Also might want to take a look at all of the pulleys. could also be a slipping fan clutch (why I went with E-fans long ago). I would suspect an old serpentine belt and dry pulleys first.

 

Check the alternator.... mine had bad bearings... went to napa and got a new one and I was good to go.

 

Thanks for the suggestions guys, I will let you know what happens!!

 

It was the belt tensioner that was shot. Cost me $120 but its all better now!