Suddenly i am noticing whisling sound from bottom rear of the car while driving.. i stopped the car without switching off the engine and tried to locate the origin of the sound. But i could not. It is some where below the dicky. ( i am not sure whether it is from the silencer / exhaust. ) But when switch off and again switch on the engine, the sound goes off... Any body in this forum experianced this ??

My fan blower makes excessive whine ( even at low speeds )though whistling may not really be word to describe it.
Whistling sound coming form the place u think ( below trunk ) is really odd. cannot think of anything there making sound remotely resembling whistling. could a busted rear hub bearing make whistling sound ? if it doesnt come while stationary and comes while driving from the place u think its coming please get ur rear wheel bearings checked.

It might also be the Turbo Whistle, but that kicks in only after 2000RPM.

or did you lock the motherinlaw in the boot If so just turn up the radio !

i have one query for @krishnasrs.
as you said the noise happens only when in motion.
i am interested in knowing skill you used to locate the location from where the noise is originating when the machine is moving on basis of which you can conclude it to be coming from bottom rear.

He lets someone drive and he runs behind it

I guess i would love to hear wistling sound in my vehicle as it doesnt make any noice. On serious note i think the engine is asking for servicing.

I had a similar problem.
They checked the Accessory belt, and the Silencer for choked catalytic converter... both were ruled out.

Finally a rusty water pump was located as the problem. It was replaced under warranty... The timing belt was also replaced along with it, since I insisted (Didn't want the machine opened again after another 15k). It was after around 35000 kms.

But the water pump will whistle up front

yes indeed.. it was upfront.
the rear end noise could be something else.

Today again the whisling sound came up... once i switch off the engine, it goes off.... and again it comes up after some time when i drive. i think it is from mufler of silencer pipe below the car.

It could then be a gasket between bits of exhaust blowing ! The only way to check is get beneath the car ( a Crazy martin245 TIP) !!!!!! Get the motor running and put something over the exhaust exit like your Shoe ! You may also hear the whistle and be able to locate it

Thanks .... i cannot go beneath the car... definitly take it to the service station and tell him check this way....

Check it yourself or get a friend to help this way you wont end up buying stuff you dont need