THE CAR LOST POWER OCCASIONALLY WHEN SHIFTING BETWEEN FIRST AND SECOND GEARS. IT WOULD NOT ACCELERATE, BUT IT REVVED TO OVER 6,000 RPMS. THE CAR WOULD PULL BACK AND THEN LUNGE INTO GEAR. IT HAD A WHIPLASH EFFECT ON THE DRIVER AND PASSENGERS. AFTER 18 VISITS TO THE DEALER AND PROBABLY AS MANY CALLS TO VOLVO OF N. AMERICA, I FOUND ANOTHER DEALER. THEY REPLACED THE VALVE BODY LAST YEAR AND IT HASN'T HAPPENED SINCE. I CAN'T ANSWER THE NEXT QUESTION BECAUSE IT HAPPENED SEVERAL TIMES A WEEK FOR 3 YEARS. *JB