Marc, push down on the left front corner of the car. Get it going up and down, then stop your pushing, the car should return to neutral with no more than a couple of inches of overshoot. If this doesn't happen, then your strut is shot. This is a rough way of doing it, but the way you describe your problem, should be a dead giveaway..

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Jeff L
1987 300e
1989 300e
1987 BMW 325