berty987
New member
As some will already know , my PASM equipped 987S has been exhibiting a low speed knock from the offside rear suspension when driving over broken road surfaces such as cats eyes etc. The problem was more evident with the suspension in "normal" mode when the car was lightly loaded and driven for the first few miles , particularly in cold weather. During summer or after about half an hours driving , the noise all but went away , it could also be minimised by switching the dampers to sport mode. After some investigation by a local independent I took the car to center gravity to have the dampers removed and tested on the test rig at bilstein. This showed both dampers had faults , one was rattly , the other was under damping. Unfortunately only the underdamping unit was considered suitable for a claim with the warranty provider , so i had to pay for the other damper myself.
I have now had both dampers replaced , the noise has completley gone, a great relief and return to an enjoyable driving experience. Interestingly , the part number on the new damper ends 20 compared to the original unit ending 04 suggesting some 16 revisions in design. The car now rides much better and it's possible to drive with sport mode activated on all but the very worst road surfaces. My suspicion is the PASM damper settings have been refined to suit real world driving conditions so that the sport mode is no longer reserved purely for the track. With a geo alignment as well, the car now feels better than ever. The dampers are to be returned to Bilstein for a complete analysis as to the fault and root cause.
I have now had both dampers replaced , the noise has completley gone, a great relief and return to an enjoyable driving experience. Interestingly , the part number on the new damper ends 20 compared to the original unit ending 04 suggesting some 16 revisions in design. The car now rides much better and it's possible to drive with sport mode activated on all but the very worst road surfaces. My suspicion is the PASM damper settings have been refined to suit real world driving conditions so that the sport mode is no longer reserved purely for the track. With a geo alignment as well, the car now feels better than ever. The dampers are to be returned to Bilstein for a complete analysis as to the fault and root cause.
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