On my E320, there is a Very annoying engine chirp coming from the main belt. I couldn't figure out what it was at first, but I stuck my head closer and closer (but not too close ) to the sound until I isolated it. I sprayed a little lube on it (the belt) to see if that stopped the chirp and it did... for a minute of so. How can I get rid of this sound? It is VERY loud all around the car and makes it sound like a POS! Any help is appreciated. Thx