Mystery Noise??

[Cashcrazy]

I hope someone has had the same issue and will share what fixed it. 2011, 2wd, 3.5 with about 108k. It has been making a whine noise while the AC compressor is on. You can hear the pitch of the whine change as the RPM's increase. I can hear it inside the vehicle, but not outside. The sound goes away when the AC compressor is turned off even if the fan continues to run. I've had some AC issues and assumed it was the AC compressor or clutch causing this, but I replaced the AC compressor, clutch, and the serpentine belt tensioner last week. The sound continues even with the new parts. It sounds like interference from the alternator, but it's not having charging issues. I really don't know where to start testing with this one. Thanks for reading.

 

[peterk9]

Is the noise still there if you turn the radio OFF?

Peter

 

[03WIExplorerLtd]

Depending on how loud, its normal. Every car will make more noise with Ac on.... a video would help to determine the extent.

 

[Cashcrazy]

The radio on or off does not effect the noise. This noise isn’t normal. I rode in a friends near identical explorer and theirs doesn’t make it. My explorer didn’t make it when I bought it.

 

[03WIExplorerLtd]

Take a video, for the sound only

 

[Cashcrazy]

I’ll see what I can do

 

[peterk9]

The

The radio on or off does not effect the noise. This noise isn’t normal. I rode in a friends near identical explorer and theirs doesn’t make it. My explorer didn’t make it when I bought it.

The A/C shouldn't make any noise if operating normally. I don't even notice mine when it's running. The strange thing is that you can't hear it outside the vehicle. I'm guessing that is with the hood up? That is why I asked the radio question thinking it might be something electrical that the radio was picking up. The things that could change the pitch that I can think of is the alternator, the belt and the compressor. I would expect to hear the noise from any of those items outside of the vehicle.

Peter

 

[TerryY]

Or Freon flow thru a restriction in the evaporator piping.

 

[chris bailey]

I hope someone has had the same issue and will share what fixed it. 2011, 2wd, 3.5 with about 108k. It has been making a whine noise while the AC compressor is on. You can hear the pitch of the whine change as the RPM's increase. I can hear it inside the vehicle, but not outside. The sound goes away when the AC compressor is turned off even if the fan continues to run. I've had some AC issues and assumed it was the AC compressor or clutch causing this, but I replaced the AC compressor, clutch, and the serpentine belt tensioner last week. The sound continues even with the new parts. It sounds like interference from the alternator, but it's not having charging issues. I really don't know where to start testing with this one. Thanks for reading.

I have a 2017 that I just noticed doing this same thing. If I accelerate you hear a sort of whiny revving, but once I turn the AC off, it goes away and all i hear is the regular engine. It's bugging the crap out of me and I'm going to take my car in soon to get it checked out

 

[Cashcrazy]

Are you still under warranty? I haven’t had time to do anymore testing.

 

[chris bailey]

Are you still under warranty? I haven’t had time to do anymore testing.

I'm at 54k miles and I'm not sure whats causing this issue would fit under the power train portion of the warranty thats still left?

 

[Cashcrazy]

It might be covered depending on what it is. Please share what they say. Do you have an appointment already?

 

[chris bailey]

It might be covered depending on what it is. Please share what they say. Do you have an appointment already?

Nah, I've isolated it that it only happens when the AC is on, so it won't be covered by warranty. Was likely going to have them check it next time I take it in to get serviced which might be a bit at 60k

 

[Adrian Gitch]

Mine does it too only with the a/c on and clutch engaged. Mine isn't very noticeable unless I turn the radio down. I had chalked it up as noisy a/c compressor. I have extended warranty so may have to look into this.

 

[Cashcrazy]

Mine does it too only with the a/c on and clutch engaged. Mine isn't very noticeable unless I turn the radio down. I had chalked it up as noisy a/c compressor. I have extended warranty so may have to look into this.

I always assumed mine was the compressor also, but the new compressor and clutch did not change the noise.

 

[Adrian Gitch]

I always assumed mine was the compressor also, but the new compressor and clutch did not change the noise.

Was the new one a ford motorcraft? Maybe these are prone to be a little noisy but some more than others making it more noticeable for some people. I’m hoping it’s nothing internal. As TerryY mentioned maybe it’s just slight restriction somewhere. I know the 3 Infiniti G35’s that’s been in our family have noisy compressors.

 

[Cashcrazy]

It’s not a motorcraft, but it was a quality brand. I can’t remember the name off-hand. The noise is the exact same with the original compressor with a failing clutch and the new new compressor that was just installed so I don’t think it’s related to that. I have to replace a catalytic converter on the first weekend I am free and then the next project will be to pull off the alternator and have it tested. I believe the test will show if a diode has failed.

 

[Adrian Gitch]

I've read somewhere that an alternator starting to go bad can cause a whining noise. My engine drops rpms and lights dim a little when I do the power windows etc.. when it's in gear and stopped or just sitting in park.

 

[peterk9]

.......... My engine drops rpms and lights dim a little when I do the power windows etc.. when it's in gear and stopped or just sitting in park.

Can't say I've noticed that on mine. I don't think that's normal. My RPMs hardly even move when the A/C kicks in.

Peter