I have an 05 F150 and for a while now it has been making a weird noise mostly while accelerating. It sounds like something is loose and making kind of a hissing noise. Anyone know what it could be?

 

We need a little more info. What engine, any mods, any work done recently, can you tell where the noise is coming from?

 

It's a 5.4 no mods and it's coming from the front driver side. I'll see if I can get a video up tomorrow.

 

Bump!
I have the same truck, making the same damn sound

 

First thing that comes to mind is a vacuum leak...

 

Sound like ice in a blender?

 

yes kind of.

 

My 04 does this when light on throttle from a stop.

 

Mine has developed a noise under load, most noticeable at lower rpms, when on the gas. Really noticed when pulling.g a 28' enclosed car hauler. Its like a hissing, whishing, sputtering sound that I fear is my right exhaust manifold leaking. It is almost like spark knock, or detonation, and happens when lugging the engine as spark knock would, but I don't.think it is. Mine only has 50k on it and the repair list is getting long and frustrating.