Well, that's what it sounds like. It just started a day or so ago. It's a whistle/whine that kind of sounds like a sick cat, and it's there at idle, and increases with RPM.
Dealership says that it's the supercharger, and it's normal. It's a different sound from supercharger whine, and it just started. Anyone else experience this?

 

I'm not a Lightning owner, but I had the same thing happen to my 4.6L. It ended up being a bad tensioner pulley bearing. I took the bearing apart, soaked it in rubbing alcohol for a little while, then repacked it with fresh grease and problem solved. Take your drivebelt off and start the truck. If the noise stops, the problem is with one of your pulleys or accessories. Turn each pulley by hand and feel for roughness. You can narrow it down from there.

 

I've been chasing noises in my belt drive for a month. This is after I repacked all the pulley bearings a couple years ago. So far I've replaced all 4 idler pulleys (2 very noisy), both tensioner pulleys (one trashed), the alternator (noisy) and the water pump (no noise, but while I was in there...). Now I have a 'cricket' noise that I think is in the bearing where the supercharger pulley goes through the cage around the crank pulley. A guy on NLOC said to remove it and go with a 2 - 4 pound pulley. I used a brake line on the end of a stethoscope to listen to each bearing. BTW - I'm at 191,600 miles, so it's time.

 

BOO to you! I was hoping for some carnage!

 

Get a wooden stick like a broom handle.Put one end to your ear and touch the other to a part of your engine you think may be bad.Test different parts and youll pretty quickly find the bad one.The noise will get very loud in the stick when you touch the bad part.
I found a bad alternator bearing like this.I could have swore the noise was the torque converter because in the truck it sounded like it was coming from the floor area by my feet.A few minutes with the stick and I found the bad part.

 

I also took your title literally and expected carnage. This happened to my mother one morning and she came into my room and woke me up screaming (I guess I was around 15 years old). She said there was a cat caught in the engine (she really meant belts) and when she lifted the hood it was trying to get out and that really freaked her out. By the time I got down to the car, the cat was toast and there was a pool of blood under the car. It was a real pain to get that poor thing untangled from the belts. I will never forget that day.

BTW, I also have a cat in my engine then. Let me know which pulley it is that's squealing. Mine comes and goes every now and then.

 

So Ford dealership says it's the supercharger. They emailed some ford engineer who said that the whine is "normal for a supercharger, and withing spec". I've been driving this thing for 5 years, I know what my supercharger sounds like.
They charged me $90 for the diagnostic, which I wasn't happy about either.

 

Just grease the idler pulleys and the noise will go away. I bought new bearings and installed them into my idler pulleys and the noise is gone. The grease dries out and you will get high pitched squeaks and whines from the pulleys.

 

Hmm.... it's definitely worth a try. Thanks for the tips!

 

just read this post and had to tell you guys.

Customer called me at my shop yesterday. Said they had a major problem.

They were snoblowing (yes, still snowing up in the boston area) and the machine stopped. They looked in front and they sucked up a cat!!!


Turned out to be a dead racoon in the end but they asked what to do.

My response was "Don't bring it here, I can't help you!!!"