Very High Pitch Sound

[Mike L]

Recently, our ‘10 Yukon XL Denali started emitting a very high pitch tone (must be above 25khz because my wife and I can’t hear it, but our kids do). It coming from the inside not outside. As I said, my wife and I don’t hear it, but our kids immediately ask, “Ugh! What’s that sound!?” after starting the truck. My wife turned on her voice recorder on her iPhone for awhile to try and catch it. Sure enough, when playing it back and turning up the volume, we heard a very high pitch, shrill sound. We have no idea where it’s coming from. Anyone else ever encounter this? Any ideas? TIA.

 

[Doubeleive]

Recently, our ‘10 Yukon XL Denali started emitting a very high pitch tone (must be above 25khz because my wife and I can’t hear it, but our kids do). It coming from the inside not outside. As I said, my wife and I don’t hear it, but our kids immediately ask, “Ugh! What’s that sound!?” after starting the truck. My wife turned on her voice recorder on her iPhone for awhile to try and catch it. Sure enough, when playing it back and turning up the volume, we heard a very high pitch, shrill sound. We have no idea where it’s coming from. Anyone else ever encounter this? Any ideas? TIA.

depends is the radio on? if it is turn it off and see if the noise goes away
if the noise remains it could be one of the temperature sensors in the headliner, there is generally 2 of them one is above the driver in the headliner and the other is above the rear right passenger, it looks like a small speaker grill, inside there is a small sensor and a fan, the fan is what could be making the noise. if you have the bose system the drivers side may have what looks like 2 little speaker grills and the passenger front will have one as well those are part of the bose system (those would not be generating any noise just the temp sensors). the sensors run about $25 online and are easily replaced.

 

[OR VietVet]

Does it make a difference if the blower is on or off?

 

[Bigkevschopshop]

doubeleve hit a good point for sure. They pretty much run when ac or heat controls are on I think, cant remember... Also my bluetooth had a alternator whine in it, wife complained for a year, I finally put a ground strap from the Alt bracket to the firewall and got rid of 90% of the whine, and also got rid of the 25htz pitch inside I used to hear from time to time. Just something to try... a 4 gauge wire from Alternator bracket side to the firewall ground strap pin that the hood ground also goes onto works perfectly. 5 minute install with right bolt and nut to fit the spots.

 

[Jetav8r7]

its the blower motor for the hvac. passenger side wheel well. remover shield and replace fan. this happened on both suburbans and tahoe i had.

 

[Matt97]

doubeleve hit a good point for sure. They pretty much run when ac or heat controls are on I think, cant remember... Also my bluetooth had a alternator whine in it, wife complained for a year, I finally put a ground strap from the Alt bracket to the firewall and got rid of 90% of the whine, and also got rid of the 25htz pitch inside I used to hear from time to time. Just something to try... a 4 gauge wire from Alternator bracket side to the firewall ground strap pin that the hood ground also goes onto works perfectly. 5 minute install with right bolt and nut to fit the spots.

Photos of your set-up?

TIA

 

[Bigkevschopshop]

Photos of your set-up?

TIA

I didnt get any photos of the setup that I remember.