C6 2007 2.7 suspension issue.

[dowen]

The rear height of the car sinks to low after about 20 minutes after ignition turned off! When I start car it goes to normal within 15 seconds, not gently, as it used to, but suddenly!
The ride is still soft and good as ever! Front is seamless through all settings. No lights on dash!
Should I be concerned?

[GiveMeABreak]

The raising and lowering of suspension whilst the vehicle is moving and when stationary is controlled by the electrovalves in the BHI:

• The opening of the inlet electrovalves and the closing of the exhaust electrovalves for raising
• The opening of the exhaust electrovalves and the closing of the inlet electrovalves for lowering

Does the car raise and lower as commanded? If so, then the electrovalves are doing their job, so it's likely to be the rear firmness regulator. There is a way of replacing the actuator only and the operation is detailed on C6 owners here to save repetition:

http://c6owners.org/plugins/forum/forum ... hp?2638.30