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I recently bought the '97 E320 . It has only 52K miles. Couple of weeks back, my wife drove the car for shopping and when she parked the car at her friend's place, she couldn't re-start the car. I went there after 30 minutes and I could start the car. I used the car a few times after that and mostly ran for less than an hour at a stretch. Couple of days back, my wife had the same problem after driving for 30 minutes and stopped at a shopping center. She couldn't re-start the car. She had lunch and after couple of hours , it started. She drove the car for 25 minutes and dropped her friend at her house. It died on her driveway. She waited for 45 minutes and it started. She drove home (less than 5 miles) and it died on our driveway. After an hour it started and she put it in the garage.
I took the car to my mechanic yesterday and he checked the battery and alternator and told me that everything is perfect. He thought that my wife key could be a problem. I drove to my work (15 miles) . In the evening, I was driving in the Highway back to house bumper-to-bumper traffic and it quit. After 45 minutes, it started . I towed the car to my mechanic shop and it is there . I don't know what the problem is... Need help....