Honda Repair: Accord - whirring sound at low rpm, vacuum leak, honda shop

Question
Accord 2000 - 70K miles
Recently a whirring sound at low rpms started.  A mechanic said it's the timing belt and it's fine.  They say that there's another 20K-30K miles left in the timing belt.  There's no change in engine performance.

Is the whirring sound alluding to a bad timing belt?  If so, can I wait another 20K-30K miles?

Answer
well first of all your timing belt should last about 100k miles so yes he was right bout the life of it. but i would reccommend replacing it before it needs it. cost between 100-300 depending if you go to a dealer or a local honda shop. and the whinning sound could be from it just being loose from stretching out a bit. u might try to tighten it. it has an automatic tensoner but you can adjust it yourself. it also may just be a small vacuum leak or a leak in the intake manifold. check the big black hose that runs all the way from the front corner of the motor to the back of the motor. check to see if it has been torn from age or whatever. more air going into the engine may also make a similar noise.