I have an on-going whine that is getting louder. Put the car in shop in april, mechanic said he tightened a pump, had me start the car (the whine was there) turn off and re-start, the whine was gone-but not for long. It is now louder than ever with no other signs of a problem. The whine changes octaves as the rpm's go up-so does the whine. Any suggestions?