Okay. Here is the latest:

* Sat the car on perfectly level concrete (my garage floor)

* Measured from the ground vertically through the wheel center to the wheel arch (fender) and wrote down that measurement for each wheel.

* Worked out the difference between my measurements and the BMW Default Measurements for my car =709 rear. 707 front, and wrote that down.

* Using INPA I go to >>Chassis >> Twin Axle Suspension >>

1) I clear the error from memory (this allows the suspension to be activated) on the car and from INPA.

2) I then go to >>Set Height>> and make sure it is >>Normal>>

3) Then go to >> Calibrate Height>> and Enter my values for each corner.

NB. To raise the car you enter your value with a Minus in front of the value, as in " -22"
To lower the car you enter the value as it is "20"
To make no change you must enter "0" do not leave it blank, that confuses the brain.

With all four values entered, and no errors on the suspension!! the car should do a dance as it re-calibrates. My car raised up very high >> then dropped very low >> then settled on the new measurements I had just entered.

Walk around the car and re-measure your heights. They should now be the same as you expected.

I now have one problem.

1) Error 116 returned after about 15 minutes of the re-set.

My next step is to check the output air pressure from my compressor at the main <speed fit> connector. This needs to be between 120 & 220 psi. I hope to be able to do this using a tyre gauge?

I suspect that my piston bore is scored and needs replacing? The plan then is to replace both the bore and the piston (again) from the wonderful bagpipingandy.com Andy has been a great help here. I had already replaced the piston ring but we suspect that bore is scored and we are just not generating enough air pressure to lift the car. Replacing both will eradicate that from the equation.

MY car has sat all night (almost 24 hours) and not lost height from where I set it yesterday. So I suspect that I have no leaks.