I have a 2004 F250 with the 5.4 with 120,000 miles. I noticed the last few months when I am sitting at a stop light or drive thru...the truck makes a humming sound. It is like a noise you get when a power steering use to whine or when the power steering had a vacumn problem.

I do know my air conditioning went out this summer. I got to looking and I think there is a hole in the AC condenser, or whatever it is that looks like and is mounted by the radiator.

Any advice, suggestions or thoughts? I could replace the AC part but I really dont need or use the AC but I am tired of this hmmmmmmmmming.

Thanks,
Randy

 

MY 04 F-250 SD 5.4 with 147K does the same thing occasionally at idle. Sounds like a deep hum or howl. Goes away when I raise the RPM slightly.

I saw a post regarding this earlier. If I find it I will post the link. It's on my list to solve as well.

If you find anything, let me know

 

I came across several post with similar symptoms- no resolution

Do you have a stock air-box or K&N? (I have the K&N)

Here are a few links that I came across that appear similar:

https://www.ford-trucks.com/forums/842904-foghorn.html
https://www.ford-trucks.com/forums/7...ing-noise.html
https://www.ford-trucks.com/forums/1...r-shut-up.html

In the last link, a guy provided a reply with three links that don't open for me. Let me know if you have any sucess.

 

My truck is all stock, including air box. Does your truck AC work fine? I'll keep you updated. Thanks!

 

Check your PCV valve at idle on the passenger side valve cover. They will vibrate when they wear and cause a noise.

 

Yeah, under the hood mine was sort of a humming or buzzing sound. It was a bad PCV valve. $4 and 1 minute to change.

 

I have a howl when I decelerate on ocassion. Pushing slightly on the accelerator the howl stop immediately. I'm thinking it is the idle air valve. 147K miles and maybe its getting clogged?

 

mine is doing this exact same thing did you figure out what it was?

 

Mine does this as well. I have the V-10. I found it to be something with the mass air flow sensor and how it is mounted inside the stock air box. I WILL figure this out. I know it is in the sensor(chamber) as I pulled open the air cleaner and it gets louder and is in that tube. I have not figured out why the sound. Some sort of plastic vibration thing.

 

With that many miles and you say at idle at stop lights or drive thu....another place to start looking is the clutch fan. Those conditions will cause the clutch fan to engage.

When I drive with my plow on the clutch fan constantly makes a hum sound because there is not enough flow thru the radiator.

Just another place to check.

 

i have the 5.4 with 101,000 miles the sound i hear goes away after about 30 seconds or immediately when i push the gas pedal? i kind of sounds like a faint horn

 

Any updates from the OP or others on what fixed the noise?

 

^ yea im still lookin for some info on this to it doesnt seem to be hurting the truck but i would like to get it figured out

 

I was having the very same issue, but I have a92 f150. does the sound only occur when you have the heat/fan blowing? I never put two and two together until my buddy turned it off one time and now I know that it's my fan.

just something to consider

 

I replaced the idle air control valve and the humming went away. The dealer by me describes the sound as a foghorn. The iac on the 5.4 is located on the back of the throttle body.

Brian