1999 Escalade 5.7L GMT-400 strange noise under dash

[Markus]

It's been driving me nuts! I am getting a strange whooshing/air/rushing/vac sound from under the dash/gauge cluster area on my 1999 Truck. The vehicle has 256k miles currently and I am specifically hearing this while stopped and idle engine. During acceleration there's a creaking sound accompanying it and the rushing sound goes away. Anyone else get this sound behind the gauge cluster?

Brake booster? Are there any vac lines directly behind the cluster or under near the drivers knee area?

Thanks!
-M

 

[east302]

The only vacuum lines would be from the booster to the intake and from the PCV valve fitting over to the heater valve solenoid on the passenger firewall.

Does it make the sound with the blower turned off?

Maybe it’s the boot on the steering shaft where it goes through the firewall? Here’s how it should look, if it’s separated push it back into place from the engine side.

You must be registered for see images attach

Sent from my iPhone using Tapatalk

 

[Markus]

Makes the sound with the blower off or on. The steering column boot seems to be seated properly. I am going to dig a bit deeper tonight.

Thanks!
-M