Whistling noise
 

I have an 04 F150 STX 2wd, 4.6L, auto, 77,000 miles. During acceleration I'm hearing a whistling noise coming from under the hood. It starts out as a low pitch whistle that gets louder and higher pitch approaching each shift point, and remains steady during cruise between 50 and 70 mph. It goes away if I let off the accelerator, but comes right back as soon as the rpms start increasing. It sounds like an air leak, but it doesn't seem to affect performance or operation of any other systems. The engine compartment is clean and all components and hoses seem to be in good condition. There are no mods, so everything is factory stock under the hood.

I have something similar (04, FX4, 5.4, auto, 4x4, 80k miles). Shows up at 49/50 mph and is gone again by 54mph. Also goes away if I let of the gas. From what I have seen this seems normal and is nothing to worry about.

Check the connections around the air filter box, and air tube to throttle body for loose clamps or cracks. It might be air entering around the air intake assembly.

This is the same noise we have been talking about in this thread:

https://www.f150forum.com/f4/weird-noise-3783/

Whistling noise solution
 

Thanks for the feedback. I've checked all the air and vacuum connections and they're all good. However, I came accross another thread on this problem and the whistling noise was found to be coming from the alternator. Apparently, the rear bearing was the culprit. The owner had the Ford mechanic ride with him and he knew what it was as soon as it started whistling. The alternator was replaced without further incident.

I'll check my alternator, but I'm skeptical. A bad bearing doesn't whistle - it squeals. My problem sounds like air being forced through a small opening. It's pitch and volume change gradually with RPM. I sounds kind of like air being released from a boiling tea pot, and it's more noticeable during cold weather. I thought it could be a sticky pressure relief valve from either the crankcase or transmission. Pressure builds gradually in both of these components and the relief valves are designed to open at a certain pressure. If the valves stick, greater pressure will be required to open them and if they only open partially, the escaping air would whistle.

Any thoughts?

I think my 04 5.4L makes the same noise and I have no idea what it is. I notice it only happens when its colder outside. Maybe 35 degrees or lower.

I have the same problem with the whistling noise in my stx.

same problem here 2007 stx 4x4

My solution is just turning the radio up, but would like to know what the problem is for sure.

whistling noise at cruise speeds 2004 Ford F150 with 5.4L
 

Mine seems to be a cold weather problem near the 2000 rpm speed and/or at cruise 62-64 mph. The belt tension pulleys seem to be okay and all vacuum hoses seem to be connected and in good condition. My F150, 4X4 is 2004, 5.4L with auto with just over 70k miles (mostly highway miles.) The temperature range with the problem has been 14 above and down to -15 degrees. The problem just stated this year. I had new tires, brakes and a new die-hard battery installed in 2009, two summers and one winter ago. The noise started just two weeks ago. I have visited a technical college and the instructor test drove the F150, he owns one also, and found the noise during acceleration, near 2000 rpm, and with cruise set. The sound would go away by backing off on the pedal, but return when speed is resumed. No noise in the shop only seems to be there under load.
A parts store mechanic dealer said that he suggests that the serpentine belt be replaced along with the belt tension pulleys. I am still using the original belt and pulleys.
Another person suggested the rear bearing of the alternator.
The only thing that I did so far was to added a can of Sea Foam to the fuel. I don’t really have any good idea of what to do. I am open to recommendations.

saaaaame problem 04 5.4L 4x4

I have the same problem in my truck. Taking it in to the mechanic this week. Been told though that its probably just cold related and won't cause any damage. Just annoying - if anyone else has an idea what it could be before I go and spend the money. Would love it :)

Same problem...Imagine that. 04 lariat 4x4

Same...04 XLT 5.4 4x4.

Whistling noise
 

My truck is an automatic and I think the whistling noise comes from the transmission vent. The vent is designed to release pressure that builds in the transmission, and usually becomes coated with a little transmission fluid. The vent is covered by a cap to prevent reverse flow of air. Air pressure from inside the transmission will lift the cap to vent the air. During cold weather the oil-coated cap won't always move freely and may only partially lift or get cocked, causing the escaping air to whistle.

The noise stops or changes pitch when you let off the throttle because the pressure inside the transmission is reduced, and unless the vent is badly oil-soaked and dirty, the whistling only occurs during cold weather when the oil is coagulated from the low temperatures. In my truck, the whistling noise is worse when the truck is cold and will usually lessen as the transmission warms, but not always. I'm at 95K miles and my vent probably needs to be cleaned, because on some days it won't whistle at all and I think it's due to the cap being stuck at full open. Remove the vent/cap assembly and either clean or replace it...you may also want to change your transmission fluid. Dirty and/or well used fluid will more easily "gum-up" the vent.

Where is this vent located. Does anyone have pics?

I have the same problem with my truck but mine is an 07 5.4L, mine is super loud and driving me nuts it only happens when I give it gas as soon as I let off the gas it stops. I've replaced the belt and it did nothing but this weekend I'm going to take my belt off and go for a quick drive to see if its the tranny and if I don't get a whistle with the belt off I know its the alternator or a pulley or something.

A buddy of mine gave me his Ford Oasis login information and I remember seeing a TSB on this same subject. I can't remember what it said, and he no longer works for Ford, but if memory serves me correct it wasn't anything major. I have the same issue. 07 4.6 XLT.

I just tell everyone its my turbo kicking in.

same noise here 05 5.4l 4x4 onl hear it sometimes under acceleration. ford couldnt find anything wrong

Same problem here when it's cold out. I have a 2002 5.4 KR. From what I have read on other boards, this is a "normal" FORD thing. No one seems to know where it is coming from. My co-worker has an 2005 f150 doning the same thing. Machanic can't find anything wrong.

< My problem sounds like air being forced through a small opening. >

Sounds like a fart to me.:D

I have the same problem but mine is from a cracked bolt in my exhaust manifold I need to get it replaced. ;)

Mine started to whistle after changing air filter. It only does it around 1500-2000 rpm. Sounds like a turbo spooling up so I haven't bothered with it.

Does anyone know where this vent is located???

anyone?

Same problem solved
 

I have a V8 4.6 in my 2005 F150 XLT and had the same problem in cold weather. After i was told that this was a "normal" noise, I had it checked and finally, they changed the alternator, the binder and a pulley but the main problem was the alternator.

Same issue with 04 4.6L XLT. Still investigating

ok, everyone talks about this vent on the tranny that makes whistling noise. Where is it??????

I have had the same problem for four winters now and it is definatley not the alternater. Its a whistle, not a squeal. It only happens sometimes in cold weather. It did happen this morning but after driving a few blocks it stopped. Tried having the dealer look at it under warranty but of course...no whistle that day! I would love an answer to this.

Same problem. first year with this truck only noticed it when it got colder.
06' XLT 4.6L.
Sounds like the 5.4 and the 4.6 are having the same issue. I'm not a mechanic. Do they have the same intake design? Do they both have this vent on the tranny? Maybe we can narrow it down that way.

99 4.6 here and I have the whistle as well. Sounds indeed like a turbo spooking up but as soon as I let off the gas it stops. Sounds like a** so I hate it lol

anyone find out anything yet?
 

I got about 2 months left on the warranty and I'm going to get to the bottom of this problem this week...i've done a ton of research on forums for the last 2 years about this problem and the best thing I've heard is that it could be the alternator or pressure valves...I'm going more towards the pressure valves cause it makes more sense and it is indeed a whistling noise like a high pressure whistle...Mine 06 4.6 stx 2wd only does it when its cold and will do it every morning when its starting up and also when its going about 30 or 55 to 60...i dont have a rpm gauge but it has to be something to do with rpm's or something...it does it when it starts up too soooo idk what the rpms are there...idk...anyone have any answers yet?

I have this annoying whistling sound too! To me it sounds as if something is spinning, almost like a scraping noise. gets higher pitch when rpms go up. I've been to my local shop and they had no idea what it is, they said possibly tranny. I went to the transmission shop and we test drove it and he said its not the tranny, because you literally can't feel it at all.

It is a definitely a weird noise and turning the radio up is my solution but i would like to know what it is!

Maybe this will help, found on google search.

TSB-08-4-2
Cold Start Fead Hoot-Whistle Noise-built before 1/c
Pub. Date Feb 7, 2008
F150
5.4 and 4.6 engines built before 1/28/08 may exhibit a front related high pitched metallic whilstle/hoot noise after a cold soak 4.4 C. Noise may be caused by the grooved nylon FEAD idler pulley.
Service procedure to correct. Replace the nylon FEAD idler pulley 6L3Z-6C348-A Idler Pully.

idler pully eh, interesting i should check that out!

Thanks.

Same issue. 2006 SCREW 4x4 - Only happens when temp is down in the freezing range.

I had that same Thing the temperature would go below freezing and i would here a loud whistle except my problem was the alternator I got a new alternator and it's never done it since all these trucks do it i guess it's the bearings

2006 SCREW 5.4 4x4 Mine does when its cold out also but it never does it until you drive for 20 min or so.

I think its coming from the transmission.

Does anyone know how the aux cooler for the trans works to maintain a normal temp. Looking at the lines to and from the trans it looks like there is a valve of some sort

2005 F150 Whistle
 

Shawnee Mission Ford in KS. Seems to think that the whistle is coming from the BRAKE BOOSTER VACUUM HOSE. Make sure you go to ford.com and enter your vin to see for recalls.

Same problem on my 08 Xlt 2wd with 30,000 on a 4.6. It only happens between 1200 and 1800 rpms. Sounds like a bad turbo spool or air being forced in through a small opening. It goes away after 1900 rpms and when I'm off the throttle.

I have an 05 Fx4 that does the same...ive looked everywhere i could think...anyone of my buddies that asks what the noise is when i drive i just tell them its a throttle body spacer :thumbsup:

I had the same problem and my mechanic took it and thought it was a pulley checked all of them and wasn't it. Thought it could be the altenator checked it and it was good. Then we moved on to the throttle body and changed everything out and still heard the noise. Checked all the vacuum lines and couldn't find anything. He was scratching his head and we started calling around and then we found the problem on mine at least. It was the vacuum line on the 4WD and it was causing it to try to engage when the RPM's got up there wasn't enough vacuum to keep it from engaging. Changed that out and never had another problem. Hope that helps!!

EB

thanks for the response but...
 

glad you found the problem out on yours. Only prob.is that mine is 2wd..does mine still have the same vacuum cables? Mine only doess it when it's below freezing and at certain rpms, basically when its about to upshift at high rpms. Idk maybe ill sort it out next winter..

Yours sounds like the bearings in the alternator mine did that exact same thing and that's what my problem was.

Same on mine. I'm having a friend check it out I. The next week or so. Pretty sure we might have found something.

Serpentine pulley bearing
 

My truck made a loud off and on again tea kettle whistle noise. Thought it was the air filter tray not sealed correctly. Then I thought it was my alternator because the noise changed to a more whining sound. Turns out it was the serpentine belt tension pulley bearing was completely shot and even hard to turn. Replaced it today and now the engine is as quiet as a church mouse. Finally!

Video link on how to find and repair this noise

http://www.fordf150.net/forums/viewt...?f=31&t=114199

Belt tension pulley bearing
 

My truck made a loud off and on again tea kettle whistle noise. Thought it was the air filter tray not sealed correctly. Then I thought it was my alternator because the noise changed to a more whining sound. Turns out it was the serpentine belt tension pulley bearing was completely shot and even hard to turn. Replaced it today and now the engine is as quiet as a church mouse. Finally!

Whistle noise from behind dash
 

Hey guys, I had this whistle noise on my 05 fx4. It drove me nuts, It started after my #4 injector stuck open and my truck went to the dealer to be repaired. When I picked it up every time I went over 2000rpm it made a whistle noise. I took it back and they tried to tell me it was a Manifold leak. I took it to a local exhaust shop and as soon as he heard it he said it was a bad cat. Well the dealer tested the Cats and said they were fine. Exhaust guy replaced the cat and WOW whistle is gone. Going to complain to the dealer but guessing it won't help.

Lol that's wat it kinda sounds like my 06 stx does it also

2007 Ford F150, i've got a whistle, sounded like a squealing belt, ran truck without belt on and still makes noise. sounds like its from the rear of the engine when i crawl under it, around the transmission, could possibly be the cat. Stutters or hesitates under heavy load (hard acceleration/up hill), anyone find out where the trany vent was?

Mines a 2003 f150 4x4 it does the same but could very well also be tires diffrent roads make noises the way the tire grips it.

Whistle fix!
 

I had a whistling sound that happened when I was on the accelerator. It happened about 1500-2000 rpms and stopped when I took my foot off the gas. I've heard some possible explanations:
Bad rear bearing on alternator (happens when cold outside)
Bad belt tensioner bearing (happens constantly)
Transmission going bad

MY FIX: When I bought my '05 King Ranch used, it had a K&N cold air intake installed. I got a used stock air cleaner and air intake assembly from a junkyard for $70. I cleaned it up, took out that CAI, and installed the stock system, and BLAMMO! NO MORE WHISTLING SOUND! No whistle, not at all, nothing! If you have a Cold Air Intake - this could be the source of the noise.

Now my engine is quiet enough that I can hear my belt tensioner bearing whining ever so slightly. Going to replace that next!

To all with the whistling noise... I bought my 2006 F150 XLT 4.6 a few years ago and the previous owner kept meticulous maintenance documents from the dealer where he had work done. About 4 months ago on a trip I had what sounded like a whistle, but could also have been described as a high pitch squeal that would change pitch with RPMs. After getting home, I began to search for the noise the next day. At first, the noise wasn't there when I started or revved the truck while in park. I drove it and everything seemed okay until it warmed up all the way. Once the truck reach it's full operating temperature then the whistling or high pitch squeal started again. I changed the belt, replaced the spring tensioner, all pulleys, had the AC system replaced and changed the alternator over the next couple of months while chasing it done in hopes of fixing it. The whistle or squeal never seemed to get worse and didn't seem to affect the operation of the vehicle, but I was concerned that it was systematic of a failure which was about to come. After knowing that it wasn't coming from any of those previously replaced items and I didn't believe it was the power steering or water pump either. So, after admitting defeat, I took it to one of my local Ford Dealerships. They couldn't confirm on the first day they had it what was going on and asked to keep it for a second day to which I agreed and didn't have any problem with. The next day the dealership called me and said that they believed it was the torque converter or pump in the front of the transmission. The price to drop and replace was over $2k. The estimate itself was $130 and the service advisor wrote that the mechanic, who was their tranny guy, "suspected" an issue with the torque converter and/or pump. I paid and left not being sure that it had been properly diagnosed and wanted a second opinion. Luckily, I have a friend who works at a tranny shop who took it in and worked on it for a couple hours and said that he wished he could tell me it was the tranny, but had to say it wasn't. The guys at the tranny shop felt sure that it was coming from the back passenger side of the motor, but didn't have time to dig deeper as they had other jobs to work. I appreciated their opinion and that gave me reason to go back to the Ford Dealership and discuss my dissatisfaction with their efforts in diagnosing my truck since they are supposed to be the experts and how I felt about the word "suspected" being used on my repair estimate. I tried to contact the Service Manager who was out and got to speak with the Operations Manager who understood my concerns and asked me to allow him to try and diagnose it again. I agreed and they kept the truck. The next morning he called me and said that he was also sure it wasn't the tranny and thanked me not having the recommended work done because he and the dealership would have had to eat the work on the bad diagnosis. He felt that the noise was also coming from the motor and thought that it may be a bad follower and/or valve and would have to remove the valve cover to confirm. I agreed and got a call from him about an hour and a half later. He said as they were preparing to remove the valve cover another mechanic asked him if they had checked the plugs. He said that is when they discovered that the back two plugs were just loose enough to be sucking air. I was going to replace all the plugs anyway and had already bought the motorcraft plugs and the MSD coil packs and told them I would bring them the parts if they could replace them all for me. He said that he would also recommend a fuel/motor system cleaning since I had this issue. I agreed to all and he said they would cut me a good price on the service. Later that day I got a call that my truck was fixed and no more whistling or squealing was evident. I paid the bill of $319 + my previous $130 for a total of $449 to replace the plugs and coil packs. I felt like it was expensive, but from all the horror stories I had heard about plug replacement on these trucks I figured it was well worth it. Big thanks to Mark the Operations Manger at Jones Ford in Charleston and all of his mechanics for the great work! What could have been another bad dealership story turned out to be a good one. Hope this helps some of you track down your issues. Sorry of the lack of paragraphing or other grammatical errors. Good luck!

Alternator. Mine went away when I got a new one

i have 2005 lariat and i get the same spooling noise what is it

who's air filter did you buy???...when I got my truck it had an aftermarket air filter in it that was a touch too short (small) as well as the foam around the air box looked great but in reality it disintegrated when I touched it...

I couldn't source a Motorcraft air filter quick enough so I went with a Fram and I noticed right away that it fit tight compared to the cheap filter that was in there and replacing the foam around the air box (I used m-d brand window seal 1/4" x 1/2" available at most any hardware store) it fixed the moan/air sucking sound as well as keeping the engine from the occasional bogging down while driving...

Good luck with yours...

Bill

This is the reason why the factory intake has all those noise-canceling baffles... mine has an Air-raid using the factory filter in factory position (looks like the factory intake without the baffles), and I hate how it sounds. More of a whoosh sound though... but the disintegrated foam seal around the air filter "drawer" would cause the higher pitched "turbo" whistle. I also went with the foam window seal.

I've got some foam window seal laying around, I'm going to try this tonight. Thanks!

Ahhh, the whistling pick-up saga.
My '06 4.6 started doing the "turbo spool" noise several years ago.
* Only when the temperature is lower than about 35F (truck stays outside, so cold soaked).
* Only after start until engine starts to warm up.
* Only at lower RPM range (+/- 900-1800 RPM).

I'm pretty sure it's the alternator bearing, but not concerned enough to replace ...yet. It doesn't stay that cold too long down here in Lower Alabama.

whistling noise
 

just started, truck warmed up, and is in a cycle. Its quiet then gets louder, and louder, and ear piercing loud, then goes away for several, several, 30-60 maybe, seconds, then the cycle starts up again. at any rpm. Any ideas? 03 SUPERCHARGED HD.

You have a supercharger... It whistles (and also whines), just like a turbo does when it operates. Also, since you apparently have a 2003, you actually need to post in the 1998-2003 forum.

The OEM alternator is famous for its bearing whine at temperatures under 40. Oddly, my truck has not done it since I did my timing job last month (but it did a year ago during winter, and all previous winters), and its been well under 40 several times.

OH, OK, I didnt notice the year thing, I'll ask in the 03 forum for that truck, and only here for my 04 Lariat. YES IT HAS A SUPERCHARGER, it's had one for the last 168,000 miles but no whistle until now.

Then that possibly means the bearings are going out in it.