2001 F150 XLT Supercrew 4x4 with 142,000 miles

Hi everyone. Yes, a 21 y/o truck with that many miles. It sat around mostly in my parents garage until a few months ago when i needed a new everyday vehicle, so they let me have him. Naturally, he hasn't been driven enough for everything that should have already gone wrong to go wrong.

I did search the threads. And Google. And Bing. My symptoms are the opposite of 95% of the threads talking about a whistle. So let's get to it.

I'm trying to diagnose a whistling that started a couple weeks ago. From the inside it sounds like feedback on the driver door speaker, but its coming from the engine. Sounds louder on the driver's side. See (or hear) attached. I hung my phone out the window as i was leaving Sonic.

The whistling STOPS when I accelerate and the engine goes above ~1500RPM. It does NOT seem to get louder or quieter when I turn the wheels.

Looked it over. Belt looks fine. Battery is newish. I don't think its coming from the alternator because it sounds louder on driver's side. Per one of the threads in here, I checked the power steering fluid. It was low/just below minimum. Added some earlier tonight. Drove about 10 miles interstate. When i allowed back down to in-town speeds, i could hear it still whistling. Then I took video to post here.

Did I miss the solution somewhere in here?

 

Oh, wait, to the person in this forum who kept saying :whistles: on every single response...**twitch**
DO NOT DO THAT, ESPECIALLY WHEN THAT WORD IS A MAJOR SYMPTOM PEOPLE ARE TRYING TO FIX!

 

Pull the belt and start it up. See if the whistle is gone. If it is, you know it's one of the belt driven accessories. Put the belt back on and use a stethoscope to narrow it down.

Check for vacuum leaks if it's not an accessory.

 

Since It'll be a couple days before I can get a tensioner tool, and my funding is short so I'm having to MacGuyver things, and its 's in the 20's and since I don't have a place to work on it aside from car washes at midnight, I thought I'd I have the hood up and you can hear a bit better and see where in the engine compartment the noise is louder.

 

Why would you need a new tensioner?

 

I have a feeling, but I'm shooting from the hip, I would say it's one of these four things in no specific order:

Idler Pulley(s)
Power Steering Pump
A/C clutch rubbing
Harmonic balancer assembly

You really need to take that belt off and see if it stops. I can pop on and off a belt on those 5.4l's with my bare hands. Easier with a slim ratchet though.

 

That was a typo. Every time I set my phone down or had to check on another app ​​or something this site would log me out and I had to rewrite it that was like the 4th rewrite.

Tensioner toolis what i meant to say. Fixed it in the reply.

 

Y'all win. I'll see if i have a socket adapter that'll work.

The Chiefs ​​​​​just won. The celebrations tonight should keep the temperature in the city above freezing long enough for me to do that.

I'll post another vid once i got it back together.

 

Took belt off.
Started.
Still whistling.

I'll post up video as soon as I get the belt back on and thaw out.

**To the mods: is necessary that I need all my comments on my own thread moderated? I know I'm new but this is a forum specifically about repairing trucks. I'm posting video. That launch so should we proof enough that I'm actually having issues and with the weather being what it is, it's kind of time sensitive. If somebody happens to be up when I'm replying here, I'd like to be able to converse a little more closer to real time.
I don't know I don't have much street cred here, but I do have a few threads over in the Chevy HHR forums (different username) I'd be glad to link you to.

 

After I shut it down I crawl underneathe. Hopefully someone can verify what is there.

 

It's not the power steering if it whistles with the belt off. However, it could be the harmonic balancer. Try a stethoscope to try to pinpoint the area. It would be a lot safer to do this with the belt off.

 

Okay I used stethoscope and prodded around everywhere. Could not pinpoint that particular sound. Could faintly hear it however the PCV valve sounds like...the only way I can describe it is it sounded like a cartoon character getting electrocuted really really loudly. That "BZZZZZZZZZTTTT" sound.

 

*The passenger side pcv by the oil cap. And i could only hear that sound with the stethoscope.

One other thing. I started it up and it wasn't making the whine, so I was about to just go home. The second I put it in gear the noise came on.

Also, it doesn't change or anything when going through gears or into overdrive. Normally, it doesn't. Just now I noticed a slight change in pitch when i pulled into this QT parking lot I'm at. The pitch rose when I gave it some gas.
​​​​​​
​​​​​​Normally once it starts, it's just going at the same pitch until i shut it off, and when I shut the engine off it takes about 2 seconds after the engine is off to die out (not an immediate stop, it peters out).

 

See last two replies. I'm pretty sure i hit all of the places where a vacuum would leak. I took that plastic cover off where the air intake connected to the engine (purple circle) and could barely hear it, like it was there, but a faint echo because the source is far away.

PCV (green) sounded weird, but I don't know what normal sounds like. No whining, just very

loud buzzzzzt sounds.

 

I'd replace the PCV valve. It's cheap enough.

https://www.rockauto.com/en/moreinfo...t=5052&jsn=480

Don't use an aftermarket valve.

Also, follow the PCV hose back to the rear of the intake, check the elbow for rot, cracks, and leaks. If it's rotten:

https://www.rockauto.com/en/moreinfo...=11784&jsn=484