whenever i start up my Disco II there's a fan or compressor that runs for the first minute then stops. it does it when i start the car. if i shut it off while it's doing it it kind of winds down and stops. I don't have the auto levelling system or anything, is it just my rad fan or something?

 

Hmm...if it spoils and winds down like you say, then its probably just a fan...you can always open the hood and start it, and jump around to see if you can locate the sound. Seems strange that it would be so loud, so fast, yet stop after just a minute. I was going to say it might be the fuel pump, but that is distinctly from the rear, and does not really have the spoil down you are experiencing. Id venture its just your fans up front.

 

It's your secondary air injection pump. Normal operation and sort of loud. An emissions device.

 

Bait is correct, it is loud though. Seems on mine when the temperature is colder it doesn't always come on.