I got a 2000 a4 with about 123000 miles on it. whenever i start up the car it kinda sounds like theres a hairdryer under my hood. it makes the noise for about 1 to 2 minutes and its pretty loud. I'm not sure if its supposed to do that or the turbos going if anyone can tell me what it might be it would be a big help.

 

Its Turbo. You only have one.

I think you should hear it whissle while driving and giving it boost.

 

probably you sap dieng........ mine did that

 

Where in there did he say he had more than one turbo?

I get a "hairdryer" powering down noise when I shut my car off. It sounds like a spaceship according to my sister. lol I don't think it's the turbo though.

 

I had the same thing, i had the intake hose for the sai come off and it sounded like a jet. Get under there and on the passenger side you will see a vacuum pump thingy, check ALL the hoses going to it. I bet you one of them came off or broke some where.

 

if you wanna know if your turbo is dying get a boost gauge and post the readings.
and he meant turbo's, a contraction of turbo and is and forgot to put in the apostrophe.