Engine noise in Santro xing

I drove my Santro Xing (eRlx petrol, Sep'2007 model) for 17,350 Km in 22 months since its new purchase in Dec'07, also I did regular servicing from Hyundai service. Recently I can hear a very little noise from the engine (I am not sure if its from engine or something else but it comes from insdie the bonnet/chasis) and the noise is quite similar to the diesel engine sound as in Tata Indica. Earlier my car engine was very silent (like in petrol engine and particularly in Hyundai santro car). There was no major accident that could impact the engine or any other parts. When I asked about the problem to Hyundai service engineer over phone, he says it could be due to the belt got loosen but not due to engine.

I would like to know from the experts about what could be the possible reasons and what is the solution.

sometime I found noise in few other Santro cars (belonged to my friend/colleagues) which clocked more than 50,000 Km or servicing not done on time, but I am not sure what could be technically wrong with those cars ?

Thanks

Suman hard to put forward suggestion without more info about the 'noise'.

Is the same always present or while startup or shutdown?

is it of a mechanical quality?

Is is a regular noise and does the 'regularity'(frequency) of the same increase as the engine is revved up?

Well.. I observed the noise almost always as long as the engine in running.

I observed the noise is slighltly more when I put it in neutral (engine in running) and come out of the car to hear the noise.

Yes..it seems to be of mechanical quality

Its regular but constant.. never decrease or increase due to any sort of engine condition

Please let me know if any further info required on this..

Suman

In my Santro (30K Odo) too there is "whining" noise, but for only a minute or two after overnight/long hours parking. Self checked. As your service guy had said, it is coming from the belt. As the car engine gets warmer, the sound recedes then regular engine sound could be heard. 

Park car. Start engine. Open hood and check it yourself.  Beware of the rotating fan.  Dont insert your hand inside the engine compartment to "feel" the sound. You would be able to sense the type of sound as to what Binoy had enquired. Post observations.

get the cam & tappet checked hyundai cars tend to make noise from head cam remove the tappet cover & see the condition of tappets & tell

EVERYDAY AT FIRST STARTING ALMOST ALL ENGINES SOUNDS MORE THAN NORMAL.THIS IS DUE TO FINE DUST PARTICLES DEPOSITED IN THE ENGINE BELT.AT THE TIME ENGINE WORKS WITH HIGH TORQUE,THUS THE ENGINE SOUNDS HIGH.

Avoid posting in ALL CAPS and in bold-MODS

Well, I guess a low "tick tick tick" sound is (or should be) normal...

Vinu could you explain/elaborate. 

Vinu howcome fine dust particles make tick tick noise?

Friends, in my case its Not a low "tick tick tick" sound, its a sound quite similar to the diesel car's engine sound (like say Tata Indica diesel engine)..