Hard to describe sound, but it only happens under load. It happens at any speed, but more predominently at higher speeds. When I lift off the gas it stops. I can keep it going up hill since I'm maintaining speed rather than accelerating over the limit.

The other day I heard another F150 beside me making the same noise going up a hill. Any ideas?

 

is it like a dieseling sound?

 

No it's not a dieseling sound.

It's always difficult to describe a sound not knowing the source. It sounds LIKE: glass beads, sand sized, being blown around inside a stainless steel cylinder. It may be a bad bearing, but I've never heard a bad bearing so I could be wrong there.

 

With that description, it sounds like the IWE is attempting to engage. Would make sense under hard acceleration as vacuum pressure would be the lowest then. The way to test this would be to do the same but with 4wd engaged. NO sound with 4wd engaged would lead me to believe that you have a vacuum leak. Just don't engage 4wd on pavement, as it could cause unnecessary bind.

 

McDavis, you may be on to something. I've engaged the 4WD while going slow and the noise present. The noise went away as soon as I enaged 4WD.

But I don't know what a "IWE" is...?

 

No worries. You really should read this:
https://www.ford-trucks.com/forums/8...then-some.html

Don't blow through it. It's a lot to read, but you'll come out knowing exactly what's wrong and where to look. Enjoy!

 

That's quite the write up on the IWE system! Good read!
Well it's going into the dealer on Monday. I fear they'll come back with a bill for new IWE actuators, IWE solenoid, check valves, yada yada yada.

 

I have the same sound. Just left a mechanics shop I have trusted for years and he said it sounds like a problem either in the starter solenoid or the flywheel.

Well have to have it checked to determine.

 

Well, I finally took the truck into the dealer today. I had a few things I needed to get done; put winter tires on (already on rims), oil change, air bag recall 11S18 (wire harness chafe on horn mounting plate), and this "noisy" problem.

It did indeed turn out to be the IWE as McDavis pointed out. Thank you McDavis They replaced the driver's side IWE and the IWE solenoid. It was covered by my extended Ford Base Care warranty.

Thanks to this forum, I bought the warranty from one of the site sponsors when I bought the truck. When I was researching this truck someone said they wouldn't buy one of these trucks without having a warranty. I took that advise and it has paid off. This is the third warranty claim in less than three years (rear diff clutch pack, and intake manifold leak).

Automotive forums are great.

 

You're welcome! Im glad it was nothing more than some IWE issues. Enjoy your weekend!

 

Hate to Necro this thread but it seemed relevant to my issues.

I have the exact same issue as OP. Going up hill hear the same sound, level off or gas off sound leaves.

One thing though, if I hit the overdrive off, the sound immediately vanishes. Any reason it would do this if it were indeed the IWE's as well?

 

Lower load in 3rd gear compared to OD. Which results in more engine vacuum, since vacuum is inversely proportional to load.

 

Thanks. that makes sense! my ac blows out of the defroster vents as well under the slightest load so i must have a vaccum leak somewhere, though i dont believe those lines are shared between those two systems. i wonder if the air res. box is? i will check with a gauge to see if it is holding vaccum.

 

Does yours sound like rumble strip?

 

Crazy, but...

One of the lift bars on my 4.2 was cracked. Took me forever to figure it out. It was the lift bar on the left rear of the engine, that's bolted to the exhaust manifold. I gave it a huge twist with my hands and there was no more rattle.

Until...

Last Friday I kept hearing a rattle. Thought it was from a piece of metal I was hauling. I shifted the load, but nothing changed. Looking under the truck it seemed that the noise was coming from the exhaust. Dang!

Anyway, it seems that looking at it stopped the rattle. (I'm famous for fixing things just by looking at them. No explanation for that, lol)

And the bad news? My engine light is on. Heading to the parts place for a code read now. BRB

And the really bad news? Cat converters for my truck run $550.00 each. Ouch ouch ouch!