Could it be the alternator? Harmonic balancer?

[treats54]

I went through and replaced the blend door and actuator. Also fixed the defrost door vacuum lever. Now the engine makes a terrible chirping sound. The belt is fairly new (about 1 year old). Tried some belt dressing but made no difference. The chirping sound is there when the car is cold. But will stop after driving for a bit if the ac/heater is turned off. Noise will now stay away after turning it back on after driving for a bit. Chirping will usually come back at low speeds, but not always after it is warm. The noise seems to be coming from around the alternator, but not sure. Have read about some harmonic balancers making the same noise. Mine seems to be directly related to the air flow.
Does the alternator play a part in the ac/heater air flow?

Also still do not have any hot air in the front of the car yet either. Not sure of that would be related. There is hot air in the back when the controls are set to the back control panel.

 

[03explorerL]

Ours makes the chirping noise whenever the A/C Compressor kicks on. I'm pretty sure its the compressor probably needing oil or something because it never does it other than when the compressor kicks on.

 

[buckwill]

run the engine, let it chirp, then turn the engine off anc CAREFULLY touch all the pulleys including crank pulley, which one is slipping will be hot,, most likely candidate will be crank,, alt, ac comp slack the belt and turn by hand all the roraring parts feel for any grumble.. buck

 

[coolbreeze48]

The only relationship the heater would have with the alternator that I can think of is, when the fan motor is turned on it will place an additional load on the alternator especially when on the high setting. If your battery is good it shouldn't make that much difference. However, if the noise is coming from your Alternator when the fan is on high or in any situation that would load up the alternator and the noise starts - could be indication of bearing going bad in the alternator. Could be other things, including the A/C compressor clutch, depends on what is being done when the noise starts.

 

[treats54]

The noise is always there when I start the car in the morning. It was staying loud permanently, but I think I always left the fan blowing to get warm air in the back. Now after driving for a bit, if the air is turned off, the squeal will stop. Once it stops I can turn the air back on and no squeal. Until I slow down or stop, then it comes back. I usually keep the front blower speed low, since I still have no heat there, and have it blow high in the back, since it does blow warm back there.
Is the A/C compressor on the right or left of the engine? The chirping seems to be coming from the left side of engine. Hence the reason I was wondering about the compressor.

 

[treats54]

I started it this morning, let it squeal for a while, turned of engine and felt all pulleys for heat, and all were cool to the touch.

 

[matt0248]

Which engine? I thought there was some sort of TSB on the AC compressor pulley/clutch on the 4.0 V6's I could be wrong. You could remove the belt and check all the pulleys to see how they feel while spinning. It seems odd that it goes away when you turn the hvac off. What happens if you turn in the HVAC into vent mode, this will not turn on the ac compressor when the fan is on, see if it still makes noise, then press the AC button to see if the noise starts. This would point to the ac compressor/clutch.

 

[treats54]

I will check on engine type. It is a 4.0 v6 flex fuel. But it is there regardless if a/c is on or off. I did try turning the air on low in the back and low in front as well. The noise was less with lower air flow. Turning blower on high in the back increased the noise.

 

[treats54]

Temperature is warmer now and noise did not chirp as easily as this morning. But still did after applying gas. Removed belt and no more chirping. Turning the alternator by hand I could hear a small squeak. Looking at the harmonic balancer, it has a few small chunks missing from the outside. Watching the belt as it goes around the balancer it does bounce a bit as it comes up over the tensioner.
Is this enough wear to be concerned about on the balancer?
How can i lubricate the alternantor without damaging anything?

 

[StangsandMavs]

First of all... word to the wise...never touch a pulley that you think might be slipping... I tried that once and my thumbprint was left on the AC pulley (the whole thing locked up). I'd say it hurt, but I couldn't feel that part of my thumb for a month or two... lol.

Second, to be sure that it really is a pulley/belt, remove the belt and start the vehicle.

Third, the accessory that has caused the most "chirp" for me was the AC a few years after I replaced it. I removed the belt and removed the single 8mm bolt that held on the clutch, then cleaned it up. That seemed to take care of noise.

 

[treats54]

The chirp is coming from the alternator side of the engine. Does not make it when the belt is removed. No difference when a/c is on or off.

But still no heat either.

 

[StangsandMavs]

The Alt side also has the belt tensioner.

They do go out and can get noisy... If you're looking to replace the belt at all, I'd replace the tensioner (and even the idler pulley if you're going to have the vehicle for any length of time) to go with it.

As for the alternator... it's very possible that the bearing is getting noisy, but I'd hate for you to go out and pick up an alternator for the sake of a bearing. The alternator has sealed bearings, so I doubt you're going to be able to lube that up very well.

 

[Wills05xlt4x4]

Removed belt and no more chirping.
Turning the alternator by hand I could hear a small squeak.
Watching the belt as it goes around the balancer it does bounce a bit as it comes up over the tensioner.

I would look at the tensioner and idler pulley..
Cheaper than an alternator and can definitely go bad as easy or easier...

 

[buckwill]

if the alt brg is cjirping, rebuild it,, easy to do, while your in there replace brushes,, if the brg is chirping then it has already failed and lubewill only put off the inevitable,, while the alt is off, spin it on worktable, put your fingernails on it spinning, u can do the same while on the engine but dont get caught in the belts, u can feel many faulty brg that u cannot hear

 

[treats54]

Buckwill- Are you saying that it is easy/possible to rebuild the bearings in the alternator?

 

[buckwill]

you dont rebuild the bearings, u replace them but yes , its easy and inexpensive,, send email and i will talk you thru it,,, once u rebuild one alternator, u can rebuild them all,,i also have source for parts usually only available only to rebuilders, professional garages,, have fun, let us know, buck,, oh and call me buck, my friends do,, buckwill is almost my full name, buck williams,, but call me buck

 

[treats54]

Thanks for the input. The culprit ended up being the tensioner pulley.