Ford F150 Humming noise coming from engine. Only does it on startup or when stopping at a light or stop sign. Doesn't do it all the time. Goes away after accelerating.
Year : 1999Make : FordYear (other): 1999Make (other): F150Engine: Triton V8 5.4L
Recently had the alternator replaced. Noise wasn't there prior to this. I have heard heat shield could be cracked. It sounds like its coming from the air intake area.
The noise you are hearing could be a worn bearing in the belt tensioner pulley or the idler pulley and also the tension could have reached it limit or is binding and when you accelerate causes the tensioner to move a little decresing the noise. remove the belt and check the pullies for play, noise and if they spin freely.
15 years working at a ford dealership
What would cause the tension to reach it's limit /or bind? Is there a way to loosen the tension?
The tensioner is self adjustable, it has a coil spring that controls the tension and sometimes binds with age. if you remove the belt, inorder to do that you release tension on the tensioner. Take the belt off and on some tensioers the spring is visable you can spray some penatrant on it and exercise it back and forth to free and the bind sitaution. sometimes you will need to replace the tensioner itself. make sure you look at the belt for wear and cracks and replace it needed. thank you, jim