During startup, engine seems to loose power and it makes engine shakes as if all pistons are not working, after about 2minutes it goes to normal.

ua, January 2010

Sounds to me like hydraulic tappets. When did you last change the oil? A build up of sludge in old oil can block narrower oilways. If its that bad, flush the engine using flushing oil. Then drain and refill with fresh oil of good quality and the correct specification, and a new genuine oil filter, could make all the difference.

ChicksFan, January 2010