S40 T5 2006 Engine Problem
 

Hello, This is my first post, I just found this forum and i am very glad to find a lot of people like me concerned about his/her car.
I have a problem with my S40 T5 2006 hope you can help me,when I start accelerating just afterI turn on the engine (when is cold), I feel like a rattle in the pedalfor a couple of seconds and then the feel dissapears til next time I start the engine from cold.
I took the car to the volvo service dealer and he told there was nothing wrong, does this happen to any of you (owners of s40)? or anyone knows what's is happening?
Thank you