04 S55 weird noise and seat issues
12-02-2011, 12:51 AM
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1999 E55
04 S55 weird noise and seat issues
2004 S55 30k miles, mint condition
I'm having two issues.
First, there is an odd groaning noise from the rear deck area - it seem to be intermittent any time the power is on (key-less go), although I don't hear it when engine is running (might still be there). It sounds like an air pump cycling.
Possibly related, my seat bladders inflate randomly - I'll be driving along, and suddenly it will pump up one of the lumbar bladders (for no apparent reason, dynamic seat is turned off).
Seat is otherwise working properly (will adjust as it should, all functions).
All air related functions (soft close doors, trunk, door locks) seem to working properly.
???
I'm having two issues.
First, there is an odd groaning noise from the rear deck area - it seem to be intermittent any time the power is on (key-less go), although I don't hear it when engine is running (might still be there). It sounds like an air pump cycling.
Possibly related, my seat bladders inflate randomly - I'll be driving along, and suddenly it will pump up one of the lumbar bladders (for no apparent reason, dynamic seat is turned off).
Seat is otherwise working properly (will adjust as it should, all functions).
All air related functions (soft close doors, trunk, door locks) seem to working properly.
???
12-02-2011, 07:34 AM
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'96 SL600, '05 S55 AMG, '06 C230
There are two air pumps in the trunk area; both on the left side. One of these is in proximity to the rear deck and works all the soft-close/locking functions. It is a vacuum pump and should only function when these functions are activated. The other air pump is in front of the left tail light assembly and controls the seat bladders. It is an air pressure pump and feeds an expansion tank directly above it, which feeds the seat bladders. It will cycle on and off as needed to maintain pressure in the system. Both are supposed to be encased in noise-reducing foam and both are easily accessible by removing the left carpet piece in the trunk.
A common pre-failure symptom is that an air pump will be noticeable by the noise it generates. As for the seat bladders, perhaps there is an air leak in the system requiring the pump to repressurize the system.
Cheers,
Jeff
A common pre-failure symptom is that an air pump will be noticeable by the noise it generates. As for the seat bladders, perhaps there is an air leak in the system requiring the pump to repressurize the system.
Cheers,
Jeff
