Suzuki Esteem 1999 1.6 litre. Mileage: 81000. At 78000 miles I had the timing belt and 2 other belts replaced. I was told the mechanic had some trouble replacing a bolt. A couple of days later I started to hear a whistling noise. I returned to mechanic and was told a bolt for the alternator was bent. 2 months later the bolt was received and installed, a 3" bolt with a groove on the end, but it still whistles. The sound seems to come from the alternator. Is it likely the bearings? Can they be lubricated by me without removing the alternator? (There is a small hole in the top of the alternator casing away from the pully.) Is this a problem that demands immediate action by me? Thanks.