I just bought a used 2007 F-150 (33k miles) and it has a 3000 mile bumper to bumper warranty. I keep hearing a whistling sound when the vehicle is in gear and it seems to happen consistently around 2200 RPMs. I only hear it when the truck is in gear and it literally sounds like somebody is whistling.

I put in a K&N air filter but my assumption is it has nothing to do with the intake system since i can't get it to make the whistling sound when its out of gear. I also put the paper filter back in and it didn't make a difference.

What could it be? Is it something I should have somebody look at before my warranty expires?

 

Lot's of us get it. For me it happens when it's cold out. You could get a cold air intake (CAI) if you want to get rid of the sound. But they are nothing more than snake oil.

 

I can here a whistle at idle when it is cool out as well. The noise sounds a lot like the whistle of a throttle body spacer.

I have not been able to come up with a solution, but I do not think that there is anything inherently bad about the whistle.

 

i get that whistle too, especially when engine is warming up, then goes away for me. seems ok though

 

I have a 04 Screw with 70,000klms on it and i get this whistling aswell when its cold out an when truck is at about 2000-2200 rpms. If i play with throttle up or down it goes away. This doesnt happen in the summer but just when its cold outside. I took it to a dealer and they were stumped. Couldn't find anything.
If anyone knows a solution let us know cause its annoying as all hell.

Thanx.

 

I have a 2001 Expedition 5.4 and had the same whistle on cold days. Last summer I put on an electric fan and this winter no more loud whistle. Maybe it has to do with the fan clutch. I don't know just throwing it out there.

 

check for leaks and split hoses on the lines coming from the intake. trace them as far down as you can.

your sound sounds a lot like a vacuum leak coming from the intake.

probably just a loose connection at the intake itself. when the rubber is cold it contracts and doesnt seal very well. when the rubber heats up it expands and forms a tight seal. that is why the whistle sometimes goes away.

 

I hv '04 5.4 and the exact same thing happened to me. Whistling at 2000-2200 rpms, but I noticed that it started doing it after I installed K & N system.. I called K& N and the tech said this happens becaust the straight tube does not have all the baffling in it that the stock one does. He said that the sound is produced from the inrush of air over the throttle blade/blades. I'm no mechanic, but it makes sense.

 

Im getting a noise at 1950RPM to 1960RPM and this is what it sounds like.

http://www.filefactory.com/file/a03b...>f150noise.wma

Is this what you guy are hearing?

Thanks Mike

 

I was getting this sound till today. I fixed mine, it was the tensioner pulley. I used a stethascope and just listened to mine

 

Thanks for all the input,

I did find some loose connections on the intake and tightened everything up but didn't notice any change. I'll try tightening things up when its cold outside, to get the best seal under those conditions.

The reason why I feel it isn't related to the intake is because I cant make the sound happen when I play with the throttle in park/neutral. I'll check for cracks in hoses as well but there shouldn't be any since the truck is only 2 yrs old.