https://www.youtube.com/watch?v=rdpD...e_gdata_player

Not my video by my truck does this. Why?

 

Mine does that too, only when it's cold! I read last year some people said it was the alternator. I just chose to live with its only when it cold.

 

I am having the same issue. I thought a pulley might bad on the the tensioner, replaced the smooth pulley on the tensioner, but no change. When I first crank it in the morning ( it was 27 this morning ) it sounds like a jet taking off, and when driving, I can hear it whistling. This only started when it finally turned off cold. At first I thought it was the power steering, but that is not the culprit. I would really like to get to the bottom of it though. If it is the alternator, would it just be the pulley or would the whole alternator have to be changed?

 

Yup the alternator. Mine does it too and I'm living with it. I'm not sure if you could fix it by just replacing the pulley.

 

If anyone else has had this issue and was able to fix it, please let us know! Hopefully I can replace just the pulley, but not going to through the trouble to replace the whole alternator... I will just live with it as long as its not going to damage anything.

 

I had same whistling noise when cold. I could hear it even more if going uphold and giving gas. It wasn't on my 04 F-150, it was 02 Explorer. Replacing the alternator was the fix.

 

Mine recently started doing this, but not as loud. It doesn't do it all the time though. Hopefully its not a big deal.