Shut up wiper!!

It's raining again, luckily the school holiday had started, else i don't know what time i can reached home! I was on my way home, ENJOYING the jam while listening to my favorite singer's songs. I was quite sleepy so the volume i turned it quite high. But somehow, i heard some noise...'karakkarak-karak-karak' every half a minute. What's that?

I stopped my cd player and tried to listen carefully where exactly the noise came from. Then i realized it's from my wiper!! Oh my, it's so loud, and besides the noise, the wiper was kind of like jumping while it wipe out the water.

I was quite happy with the wiper 2 days ago, why? Before i cleaned the wiper, it can't really clear the the wind screen properly. I even had trouble driving when it's raining heavily cos i can't see clearly. I thought i have to change the wiper till last weekend when i washed my car, i used a cloth to clean the wiper. It's very dirty, my cloth turned black after cleaning it. After a few wipes, it's able to clear the wind screen clearly! How i know it works? cos after washing car i headed back home from my hometown and it was raining mar.. So how come it's ok two days ago and now it's not ok?

Perhaps it's too clean?? ~sigh...