Hey guys, Whats this noise at startup?

[BadBowtie03]

Hey everyone.. Im having this little noisy problem or a very weird normal noise for hondas but i doubt that.. Ok this is the thing.. Whenever I first start the car up... it doesnt matter if its cold or hot.. The engine compartment makes a strange vibrating or growling noise and then it goes away.. Sometimes the nois is 2 seconds long or 7 seconds long it just depends... Is this normal? I wouldnt think so. Anyways if I could spell the noise out it would be ----> buuuuurrrrrrrrnnnn with a little vibration thrown in but nothing major.. Its not a metallic sound and it doesnt sound real serious... No check engine light and everything works perfectly.. Its really an innocent noise it seems but just wondering what it is and If i need to fix something... Thanks everyone.

Oh and by the way its a 94 accord EX manual