Hey I have a 2000 ford ranger 3.0 Liter 4x4. I have been having a weird chirp/squeak noise when I accelerate. I changed my rear u joints, had my rear differential checked, and replaced the camshaft synchronizer. I can't seem to figure out what this noise could be. I doesn't make the noise when idling only when driving. After a little while of driving above 45mph it stops. Its a loud obnoxious noise and I could really use some help.

 

When it is making the noise, stop the vehicle and REV the engine, see if it still makes the noise, you are seeing if it is engine/clutch/torque converter RPM based or output shaft/wheel RPM based
Also when it is making the noise, shift to Neutral, and REV engine, same test as above, you are determining what area of the drivetrain is making the noise


If it seems to be engine RPM based then do this
When engine is STONE COLD, i.e. sitting overnight
Loosen fan belt and remove it from crank shaft pulley

Start engine, Battery Light will stay on, thats OK
REV engine, with no fan(or water pump) engine bay will be VERY QUIET, so even small chirp from engine/clutch/torque converter can be heard.
You can ONLY run engine for 2 minutes without water pump

If no noise is heard shut off engine.
Then spin each accessory pulley by hand, you will find one that is loose or "feels" funny.

And it could be time for a new fan belt, if you got one recently then you didn't deGlaze the pulleys, so new belt would still squeak, not as bad but still make some noise

 

The noise only happens when the truck is in motion. The noise started while I was driving this morning so I shifted to neutral and revd the engine and the noise continued the same as it was.

 

So not engine or torque converter.

2000 Ranger 3.0l 4x4 could have PVH auto hubs up front, or Live Axle(front drive shaft always turns)

Which do you have?

 

I have the Live Axle

 

Well, my dad's ford ranger was having the same issue, Just replaced the fan belt and it resolved.

 

If noise comes back, then you will need to Deglaze the pulleys.

Get some Emory Cloth, flexible sand paper
Remove fan belt
Rough up the surface of each pulley

Fan belt works by friction
When a belt starts to squeal that means it is Slipping on a pulley, and that slipping Glazes that pulleys surface, makes it like a glassy surface at that spot.

When you put on a new belt it will grip better, but it may start to squeal again after a few weeks or months, if so Deglaze the pulleys
Painting pulley surfaces helps as well, as long as the paint sticks

 

I just replaced the Serpentine belt last night and it is still chirping. It sounds more like its coming from the back of the truck. Any other ideas of what it could be?

 

Noisy rear UV joint ???
When you shifted into neutral was the truck still moving ?
That would keep the UV joint turning.

Jack up the rear and use jack stands on the axle.
Block the front tires too, for and aft.

Start it up, put it in drive and listen.

EDIT, never mind, you said you changed the rear UV joint.
Even then put the front on jack stands as well and listen, something may show up.

 

Do bumps seem to affect it? tailgates rattle like crazy sometimes and squeak like mad at the latches., my ranger the rear spring bushings squeak as well.
jack the rear wheels up and rotate a wheel and see if you can make a squeak - lightly rubbing brake parts will squeak as well.

ive had exhaust parts rub on things and thats like nails on a chalkboard - check it out thoroughly as ive had to not rub when cold but as it heats up it expands (in length) and would rub once it was hot.

 

water pump ? on my older vehicals it was usually Fan belt or water pump sometimes on rare occasions Power steering pump

 

Thank you for your advice..