Fan whine/siren noise on engine start up

[cmore]

Does everyone have a whine noise that sounds like a jet engine taking off a few seconds after starting the engine? Sounds kind of like a quiet tornado siren. I am pretty it is part of the fans/AC as it is not RPM sensitive and doesn't do it if I have the fans turned off. Well lately, it has been going on and off and it sounds like where it is a ambulance is coming. The whine last for a few seconds and increases in pitch, then it stop for a 1/2 second, and starts all over. It does this for about 10 minutes after driving and doesn't stop.

Any idea?

Thanks,
Chris

[JRS-RS6]

It reminds me of preflight as a jet is preparing to take off.

[cmore]

Do you know what is the whine? fans?

Do you have the problem on hot days where it keeps starting over and over? Sounds like a pre-flight noise over and over.

[ben916]

It almost sounds like the secondary air pump or something pressurizing...
Mine lasts about 1-2 minutes and then spools off/shuts down...
You can def tell when it is running as it sounds like one of the roller is in need of some grease...

I do hear it at other times, it will re-pressurize...