At your mileage, it would be a good idea to replace your nitrogen cells, which are a component of your self-leveling suspension. They are often the cause of a problem like yours, and even if they're not completely shot they're due to be replaced.

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"If God had meant for us to walk, why did he give us feet that fit car pedals?" Sir Sterling Moss

Michael
2014 E63S Estate
2006 SLK55
1995 E500
1986 Porsche 944 turbo