I have a 2001 F150, 4.2 V6. Since I bought it there has been a couple of weird rattles. Any advice or help would be so greatly welcomed. It is starting to get annoying have these noises.

The first is when you turn the steering wheel to far. Now this can shake the whole truck if it goes to far. I thought at first it was low power steering fluid but it wasnt. I took it to a family friend who was a mechanic for 20 years. He said it was just "harmonic vibrations". It comes and goes. That isnt the worst one.

The second is when I am in idle. Its a low rattle that sounds like it is coming from the front of the truck. But as soon as you hit the gas even a little, it goes away completely. That one also comes and goes. Sometimes it goes weeks with out making a noise.

The third is the most annoying. It sounds like my truck is taking off. It sounds like metal rattling against metal. It is really bad in the morning or if its been sitting for 6+ hours. It is also bad when you first it the gas and take off. I was thinking it was the heat shield over the muffler but that isnt loose.

Any thoughts?
Thanks

 

Belt tensioner 100%

 

For which one? lol

 

All the above

 

yea...and the low idle could just be wear.
My mustang does that after 180,000 miles but shes still strong.

 

The tensioner tends to not last even if you put a motorcraft tensioner it's gonna last about 40-60k miles it's not hard to put in but that's the noise mines gone right now and it's usually worse if this weather is cold out its not bad but any pressure put on the pulleys is gonna make noises

 

My exhaust rattles every once and a while up front before the pipe comes into a y. I found that there is a exhaust mount there that had come apart so the metal peices bump against each other every once and a while when it idles