Strange whirring noise coming from defrost in 2012 LS2 Camaro - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

DJDBumblebee · 11-21-2020, 12:14 AM

https://youtu.be/vmF3yIlddCE

I'm completely confused by what this noise could be. I know for sure it isn't the blend door. I replaced it a year ago by cutting through the trim by the drivers side floorboard. It's still accessible and that's not the issue, as the sound is not coming from down there. I certainly didn't hit the heater core, either, so it's not related to the blend door. I replaced the cabin air filter a few weeks ago hoping it would fix it, but it changed nothing. I'll check the fresh air plumbing, but it doesn't do it for any other vents when the fresh air is active, so I doubt it's that, either. My car is garage kept and I don't park under trees, so I can't think of how anything may have wound up in there. The serpentine belt is new, replaced it last year, and I know it's not the compressor or the condenser. It sounds like a bearing in a fan, coming from where the windshield meets the dash and can be heard from both inside and outside the vehicle.

If you turn the volume up and hold the speaker up to your ear, or use headphones, you can hear it clearly in the video. It only does it on defrost, not any other vent option, regardless of if the recirculation button is on or off.

I went for the simplest repairs first but it's still making the same noise. I'm hoping to figure out what it is soon. I'm at a loss.

tomlink · 11-21-2020, 10:41 AM

Sounds like your AC compressor to me. Are you getting cold air with AC or defrost on?

DJDBumblebee · 11-21-2020, 06:51 PM

Quote:

Originally Posted by tomlink

Sounds like your AC compressor to me. Are you getting cold air with AC or defrost on?

It's definitely not my compressor. The air is getting cold and it doesn't make a sound on any other vent option.

tomlink · 11-23-2020, 06:06 PM

I still think you have a problem with the compressor. The AC compressor runs whenever AC is selected or Defrost, and that is exactly what you demonstrated in the video. If you still get cold air it isn't completely broken, but there is definitely something wrong with it.

DJDBumblebee · 11-23-2020, 06:31 PM

Quote:

Originally Posted by tomlink

I still think you have a problem with the compressor. The AC compressor runs whenever AC is selected or Defrost, and that is exactly what you demonstrated in the video. If you still get cold air it isn't completely broken, but there is definitely something wrong with it.

It does not make the sound when the AC is on when any other vent is selected. Only on defrost.

InFiD3ViL · 11-23-2020, 07:48 PM

It sounds like the compressor to me too, but it makes no sense to only do it when the defrost is on, but not when switched to regular AC. That's some weird stuff.

DJDBumblebee · 12-09-2020, 07:44 PM

Replaced the AC compressor today and still have the same noise. It's NOT the AC compressor.

11-21-2020, 12:14 AM	#1
DJDBumblebee Drives: 2012 2LS Coupe Join Date: Apr 2014 Location: Louisville, KY Posts: 16	Strange whirring noise coming from defrost in 2012 LS2 Camaro https://youtu.be/vmF3yIlddCE I'm completely confused by what this noise could be. I know for sure it isn't the blend door. I replaced it a year ago by cutting through the trim by the drivers side floorboard. It's still accessible and that's not the issue, as the sound is not coming from down there. I certainly didn't hit the heater core, either, so it's not related to the blend door. I replaced the cabin air filter a few weeks ago hoping it would fix it, but it changed nothing. I'll check the fresh air plumbing, but it doesn't do it for any other vents when the fresh air is active, so I doubt it's that, either. My car is garage kept and I don't park under trees, so I can't think of how anything may have wound up in there. The serpentine belt is new, replaced it last year, and I know it's not the compressor or the condenser. It sounds like a bearing in a fan, coming from where the windshield meets the dash and can be heard from both inside and outside the vehicle. If you turn the volume up and hold the speaker up to your ear, or use headphones, you can hear it clearly in the video. It only does it on defrost, not any other vent option, regardless of if the recirculation button is on or off. I went for the simplest repairs first but it's still making the same noise. I'm hoping to figure out what it is soon. I'm at a loss.

11-23-2020, 07:48 PM	#6
InFiD3ViL Drives: 2010 CGM 2SS/RS LS3 Swapped A6 Join Date: Sep 2016 Location: Spring Hill, FL Posts: 4,576	It sounds like the compressor to me too, but it makes no sense to only do it when the defrost is on, but not when switched to regular AC. That's some weird stuff. __________________ 2010 CGM Camaro 2SS LS3 Swapped A6 - GPI LS3 SS1 .647/.638, (224/237, 112 +4, 7º overlap) on CamMotion 8620 core, BTR Platinum .660" Dual Spring kit w/titanium retainers, CHE bronze trunnion upgrade, stock heads milled @ .015, Melling HV 10296 oil pump, TSP 1-7/8" long tube headers (W/Catless Off-road Pipes), Corsa Xtreme 3" Catback, GPI Ported/Rod Mod Intake, Stage 2 Ported Throttle Body, Vararam OTR CAI, Mike Norris Gen 2 catch can + GM 1LE clean side separator, 160º thermostat - Megan Racing adjustable coilovers (lowered 1.75"), MRR M017 10/11" wheels-Tuned by Ryan @ GPI

11-21-2020, 10:41 AM	#2
tomlink Drives: 2011 Camaro 2LT RS Join Date: Apr 2011 Location: New Bern, NC Posts: 953 View My Garage	Sounds like your AC compressor to me. Are you getting cold air with AC or defrost on?

11-23-2020, 06:06 PM	#4
tomlink Drives: 2011 Camaro 2LT RS Join Date: Apr 2011 Location: New Bern, NC Posts: 953 View My Garage	I still think you have a problem with the compressor. The AC compressor runs whenever AC is selected or Defrost, and that is exactly what you demonstrated in the video. If you still get cold air it isn't completely broken, but there is definitely something wrong with it.

12-09-2020, 07:44 PM	#7
DJDBumblebee Drives: 2012 2LS Coupe Join Date: Apr 2014 Location: Louisville, KY Posts: 16	Replaced the AC compressor today and still have the same noise. It's NOT the AC compressor.