Greetings all!

I have a 99 F-250 Super Duty, 4x4 and V-10 powered. Awhile back, I noticed after making a sharp turn, I would then start to hear a squeak/chirp that was RPM dependent. With the gas depressed, the noise was there. Foot off the gas, it instantly went away. Early on, the noise would go away after a bit, until I made another sharp turn, an then it would return.

In the last few weeks, the noise has been present more often than not. I don't hear it right away after driving off, but within a few miles it starts and stays. Again, it is purely RPM dependent. Gas on=squeal/chirp, gas off=silence. (Note it is not speed dependent. The noise frequency doesn't change with speed or gear position, only throttle position.)

My thought is it is probably related to the vacuum system, and likely has something to do with the auto hubs. (The noise sounds like it comes from the right front, but I'm not 100% on that.)

Has anybody else experienced this? Anybody have the solution?

 

Nobody ever responded to this, so I must be the only one in the world experiencing it. Woulnd't be surprised since it still hasn't been diagnosed/cured.

As for an update... The problem only occurs when the vehicle is warmed up. The hubs and drivetrain have been ruled out. I had my trusted mechanic drive the truck for several days and try and figure out what the noise is and he came up blank. He thinks the sound is coming from up under the dash, or at least the back of the engine. Again, the volume of the noise is throttle dependent. Max throttle = max noise. Let up off the gas and it goes away.

I keep hoping something will break... to figure out what it is and to fix it. No luck so far!

 

Belt or belt tensioner.
Or it could maybe be thee power steering pump.
I'd replace the belt and tensioner.

I still had the stock belt and tensioner and at 300,000 km's it shredded, took out the plug on the AC unit.

afteer it was replaced, my squeek went away.

 

Thanks for the reply!

Belt and tensioner have been replaced. So has the alternator and A/C compressor. I doubt it is the power steering pump since the noise doesn't change when turning the wheel at all.

The fact my mechanic thinks the squeak/chirp is coming from up under the dash leads me to believe (as I have all along) that this noise is vacuum related somehow. But what the cause is.....

 

This may be a dumb question but how about the idler pulley?

 

I've got the "chirp" going on with my truck too. I took the belt off and it still does it. I haven't been able to track it down. Any ideas?

I'm taking it in to my mechanic later today to schedule an appointment.... gonna try to get it in this week. I'll keep yall posted.

 

No, not dumb. I haven't changed it, but it does spin freely when the belt is off.

 

I don't think it's the idler wheel that squeeks, its the pivot elbow thinger.

 

I'm not looking under the hood at the moment, but I believe there is both a spring loaded belt tensioner and a separate (fixed) idler. The tensioner was replaced when I replaced the belt and the idler was only inspcted visually and with the finger (spin & wiggle) test.

Again, what makes me think it has nothing to do with the belt and accessories is the fact I can control the noise with the throttle and engine load. (My truck is a manual transmission and I can run at a given speed in a given gear and I can induce/remove the squeak/chirp by dipping in and out of the throttle.)

One other thought I had was that it might be related to the pilot bearing or bushing (I don't know which it has). I thought if transmission was slightly loose, (or maybe some other cause), that the busing/bearing might be making the noise when under load. My mechanic doesn't think that is it though.

I figured with as many Super Dutys that are on the road, that SOMEONE has experienced this as well. (Oh, and has a cure!)

 

engine mount?

 

A friend of mine replaced his, and it still squeaked, till he got an oem tensioner.

sometimes oem is better