Hi all Firstly thanks for all your great info. I have a 97 80 series auto and it seems to have developed a persistent whistle under acceleration. I first noticed it when I put my foot down to take off around a left hand corner now it does it all the time at around 2100 rpm to about 3000 rpm under load (when accel.). It does it in all gears but not neutral. It's slightly worse up hills. I can only hear it with te windows down. I have inspected the exhaust but cannot see any evidence of holes or a leak. Could this be an intake problem or an exhaust problem? Any help or ideas would be greatly appreiated.