Reduce Loud Rattling sony vaio CS fan noise

Update: 3 months since my post on reducing the fan noise. The noise seems to reappear. I took apart my vaio CS again to peep inside and try to figure out what exactly is the problem. I found that there is a lot of wobble when the fan rotates which makes the blades to brush the edges. So i came up with this.
Take a smooth surfaced plastic washer and stick it to the base of the center rod in the fans, like this in the photo. Look at the arrows to see how the washer is stuck to the base of the fan. After this put everything back as before. Now the fan noise is very minimal as the wobbling reduces to a great extent and the fan runs smoothly. For full article look below.

                                                                 

Hi it has been nearly 10 months since i started using vaio CS17G, it is an excellent laptop running vista without problems thus far. But since yesterday i started getting a strange loud fan noise all of a sudden.
I could follow the temp readings and the noise came on as soon as the temp was nearing 50C.
After googling for a while i learnt that this is a common problem with the sony laptops and was attributed to the faulty fans manufactured in china which were used by sony for their laptops.
I could go for repairs from sony under warranty, but for many people the problem returned after the repairs.
Since i had also partitioned the hard disk and installed ubuntu, i was not sure of warranty.
So i decided i will fix this on my own.
So these are the steps to reach the fan and fix the problem.

1. Disconnect power cable after shutdown and remove battery.