2004 buick rendevous cxl

MY CAR HAS A AIR LEVELER SYSTEM [FACTORY]

VERY INTERMITENTLY IT WILL MAKE A HIGH TONED WHISTLE SOUND, CAN’T TAKE IT TO DEALER BECAUSE IT DOESN’T DO IT OFTEN ENOUGH, SOUNDS LIKE IT’S COMING FROM EITHER THE DASHBOARD OR FROM UNDER THE HOOD.

A AUTO RADIATOR MECH. SAID IT MIGHT BA A CHECK VALVE IN THE AUTO/HEAT/AC , SYSTEM BUT I TRTIED GOING FROM HEAT TO COOL, IT WILL NOT MAKE THE SOUND, AND OF COURSE IT WILL NOT MAKE THE SOUND WHEN I TAKE IR TO A DEALER. I WILL APPRECIATE ANY HELP, THANKS.

STOP YELLING!! Or - in other words - turn off the all caps button.

This doesn’t have anything to do with the air leveler system which only has air lines in the back and if they did leak your compressor would run all of the time.

If you want some suggestions it would be very helpful for folks if you could say some more about when you get this whistle sound. Is it at idle? Accelerating? Decelerating? Cruising? Just starting out? Cold engine only? Warm engine only? Do you have any reason to believe that it might be associated with the heating/cooling system?

I understand that it is intermittent, but what have the circumstances been when you’ve have heard it?

And you don’t need to go to a dealer. Find a reputable, local, independent mechanic.

Under the hood is a good place for the noise to happen, the pump is there.

can do it at any time,after first start, prior to shut down, after shut down. i can’t say it does it while driving. i have tried changing from heat to cooling, i tried going from neutral to drive and reverse. the only reason i talked about the heating/cooling was that a auto/ac man sid it might be a “check valve”.again i can’t get it do do the noise at any particular time, THANKS

what “pump” are you refering to, i thought the air leveler pump was on the rear at the rear axle. THANKS