Guardian64

2015 F150 2.7 Eco Boost With 23,000 miles

Makes the strangest noise when I'm going down the road on cruise control around 40 mph (happens at various speeds but most common at 40). Has happened at various outside temperatures from 23F to 76F. Sound will typically last a few seconds however if it comes on going up a hill it will last until I do something to slow the truck such as braking or disengaging cruise control. Sound always goes away instantly whenever I do anything to slow the speed of the truck. Sound is a loud mechanical scraping/grinding noise. Sounds like your dragging a piece of sheet metal or what I would imagine sounds like a number of metal cans thrown in a blender. Sound comes from the engine compartment and vibrations can be felt in the pedals and floor. I've taken it to the dealer and was able to replicate it on a test drive however they still don't know what it is. They tested the vacuum system and said it was good. Here is a link to a video of a guy who seems to have experienced the same problem I am having. The audio is a little week in the video though and it is much louder and intimidating in person.
Please HELP!!!

Crownman

Do you have the A/C on when it happens? If so, see if it does it with the A/C off. The way it stops so suddenly make me think it could be the A/C compressor. The A/C clutch engages and it slowly starts to make noise. Then it stops in an instant when the clutch disengages. If the clutch isn't fully connecting with the a compressor they'll be spinning at 2 different speeds and sound like metal rubbing.

Guardian64

I haven't noticed a difference with A/C on or off but I'll pay closer attention to that now. Thanks for the tip.

doctorschlachter

Is your truck a 4x4?
Sounds like IWE or check valve issue perhaps.

If it is a 4x4, put it in 4 high and see if the sound goes away.
This will confirm.

Another thing to check is loose exhaust shields just to eliminate the possibility.