Home AC making unusual sound....

[David Paul]

The outside unit of my 5 year old Lenox AC has started making an unusual sound. While running, it sounds like it is "hunting" for the right speed. It is a single speed unit. It's cooling the house but also seems to run for a long time between cycles. But again it's been hot here in NJ.
Thanks for your thoughts.
David

 

[crabjoe]

When the sound of my compressor started to oscillate, on my old York unit, I was a bit low on refrigerant. Even after it was topped off, it always did it. My neighbor's York unit is doing it too and the thing is so loud, I hear it in my house. Maybe I'm more sensitive to it because my new Rheem unit is so quiet.. no idea...

As for your issue, unless you have some testing equipment, I'm not sure what you can do other than making sure everything is clean... Make sure all leaves, grass clipping and what not are not impeding air flow. Take a hose and wash all the coils out to and see if it still makes that odd noise.

BTW, unusual sound is kind of vague, what exactly does it sound like?

 

[David Paul]

When the sound of my compressor started to oscillate, on my old York unit, I was a bit low on refrigerant. Even after it was topped off, it always did it. My neighbor's York unit is doing it too and the thing is so loud, I hear it in my house. Maybe I'm more sensitive to it because my new Rheem unit is so quiet.. no idea...

As for your issue, unless you have some testing equipment, I'm not sure what you can do other than making sure everything is clean... Make sure all leaves, grass clipping and what not are not impeding air flow. Take a hose and wash all the coils out to and see if it still makes that odd noise.

BTW, unusual sound is kind of vague, what exactly does it sound like?

Thanks crabjoe, good points to check. The noise is the varying sound of the compressor itself, up and down in speed. Like the old carbureted cars "hunting" for the right idle speed. (Usually caused by a vacuume leak)

 

[crabjoe]

You may never have a problem, even if it sounds like that. My old York unit did it for years and the only reason it's not is because I replaced it.

I wonder if the problem might just be that some of the screw are lose or some weather/foam tape is getting worn to a point, that it's causing a the sound.. Try just tightening up all the screws you can get to and see if that helps.

Good Luck!

 

[zmaxmotorsports]

When the sound of my compressor started to oscillate, on my old York unit, I was a bit low on refrigerant. Even after it was topped off, it always did it. My neighbor's York unit is doing it too and the thing is so loud, I hear it in my house. Maybe I'm more sensitive to it because my new Rheem unit is so quiet.. no idea...

As for your issue, unless you have some testing equipment, I'm not sure what you can do other than making sure everything is clean... Make sure all leaves, grass clipping and what not are not impeding air flow. Take a hose and wash all the coils out to and see if it still makes that odd noise.

BTW, unusual sound is kind of vague, what exactly does it sound like?

Older York compresses always reminded me of somebody being trapped inside of a 55 gallon drum trying to beat their way out with a hammer.
I

 

[davejo]

I have an outdoor unit that oscillates too. Its loud and sounds like sheetmetal vibrations. The rpm speed is constant but the vibration waxes and wanes in a regular pattern: waaah waaah waaah waaah like a sine wave

Mine is a carrier 5 ton that cools great but is annoying to listen to. Supposedly "serviced" when we bought this place last fall

I don't know how scroll compressors are supposed to sound but i've heard other units make this sound and was annoyed by them, too

 

[zmaxmotorsports]

I have an outdoor unit that oscillates too. Its loud and sounds like sheetmetal vibrations. The rpm speed is constant but the vibration waxes and wanes in a regular pattern: waaah waaah waaah waaah like a sine wave

Mine is a carrier 5 ton that cools great but is annoying to listen to. Supposedly "serviced" when we bought this place last fall

I don't know how scroll compressors are supposed to sound but i've heard other units make this sound and was annoyed by them, too

Set a small brick dead center on the top and see if if goes away,probably a fan motor bearing or bent blade.

 

[LS6 Tommy]

David, where are you in NJ? If you're not too far away I can come by and at the very least take a look at it.

Tommy

 

[davejo]

Set a small brick dead center on the top and see if if goes away,probably a fan motor bearing or bent blade.

Good tip. Fan looks to be running a nice true circle.

The sound is definitely emanating from the compressor component down there in the depths