I've searched this forum but could not find anything related to my problem.

I took my car for my first service, i believed its "A1". After i took my car home, i noticed a hissing sound coming from my car while i pressed the throttle slightly hard right before it shifts down a gear. Never had this problem before my first service. I was wondering if anybody in this forum had this problem.

Do anybody know? or do i have to take it back to the dealer so they can find the problem?

Thank you in advance.

 

I apologized. Makes a hissing sound right before it shifts to the next gear.

 

do you have a moonroof visor?

 

I had this problem in my CL a while back. Turned out the the dealer didn't put the Air Filter cover on properly (wasn't making a good seal). I simply removed and reattached the cover - problem solved. Good luck.

-Mike

 

No, I don't have a moonroof visor.
I'll check the air filter cover, i hope that works.

Thanks in advance