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Chevy Tahoe

I have an 05 Tahoe. I noticed some time ago that when I sit and idle for a long period of time the car developes an awful noise. It sounds like and airplane taking off. It used to be that after driving it for a few minutes it would go away. Now it happens alot. Sometimes not even after idling for a long time. It is a low pitched whirring. It feels like it is in the front end-right under my feet.

Simple, it’s the De-clutch on you fan activating. Means the sensor in the radiator sense the radiator heating up and activates the fan. Can encounter the same going up a long incline on a hot day.

Would that be an airplane like a Cessna 172 or maybe “Iceman’s” F-14 from “Top Gun”?

I worked at Kloten airport in Zurich Switzerland and when those Soviet cargo plane took off it was like a fleet of 747’s. I could not believe one plane made so much noise. Pretty neat when an Israeli plane landed, two armoured cars came out.

BTW idling for a long time is not very good for your car’s engine.

Simple-I’m not an idiot. I know what the fan sounds like. It’s not the fan. But thanks.

Does the temp gauge creep up when at an idle, say longer than waiting for a green traffic light?

If you listen under the hood when this noise starts what area do you suspct it’s coming from.

Have a listen around the throttle body.

The Brake Pressure Modulator Valve (BPMV) is located right under the driver on this vehicle. I have seen these fail and cause the type of low pitched whining you are describing. The next time it happens reach under the truck and you can touch the module to see if it is where the whining is coming from. Pull the ABS fuse and see if the noise stops.

The only fix for a failed module is replacement and they are very expensive.