hair trigger sls ?

[antony]

i have a self levelling suspension question i'm hoping someone can
help me out with...

i recently replaced the sls accumulators since the sls was constantly
cycling while i was driving. now, it seems like the car is maintaining
a proper ride height; e.g. if i put the key in the ignition and then
climb in the trunk, the sls activates for 15-20 seconds, and when i get
out, i find the rear wheel arches are about .5 inches higher.

however, when i get in the trunk, the sls activates after about 5-6
seconds, and when i get out, it releases in about 5-6 seconds. is that
normal? from what i've seen in diagnostic procedures is that the sls
should take on the order of a minute to respond to position changes.
what could cause it to respond too quickly ?

thanks in advance,

--antony

[bbojangles]

key is turned on. 5 seems a bit short.

[scottiesharpe]

It is my belief that the SLS should NOT operate after its initial adjustment. You would need to turn the ignition off and start it again for it to get the new setting. I am not 100% certain on this however :)Scottie Sharpe
Provider of Mass Air Flow Conversion Kits for BMWs
www.scottiesharpe.com/store

88 Dinan-badged M5, M88 motor with BTP mass air flow conversion, Dinan Stage 4 suspention, Dinan 17x9.5 3pc wheels, 255/40 Conti Sport X 4, Racing Dynamics software, e34 rear brakes, B&B Stainless steel Exhaust, F&R LaDue stainless steel strut bars.
91 318iC
73 Bavaria
67 1602 Ireland coil overs, brembo brakes, Dual Solex 40 PHH
Do you BMWwikiwiki.com ??

[bbojangles]

as long as the key is in the ignition positions, mine adjusts whenever the height changes... there are 3 things that stop if from adjusting:
1) the timer being discussed here
2) there are mercury switches that detect movement of the car
3) applying the brakes

[antony]

interesting.

i guess what i forgot to mention is that what started my looking into this is that i was noticing "odd" handling traits that i thought might be the result of the sls doing its thing while driving.

i didn't know there were mercury switches involved; how would i go about confirming that they inhibit sls action while underway?

tia,

--antony

[Bruce in Canada]

disonnect the pump under the spare tire.
The mercury switches are inside the height sensor screwed to the bottom of the car, near the sway bar.
the electrical plug for the switch is under the back seat on the driver side. you can unplug that and disable the system too.. that is only one screw and easier than emptying the trunk.


I doubt the thing is adjusting when you are driving.. the switch looks reliable inside. I had mine apart just 2 weeks ago.

[Randomg]

I'm not positive it's the pump, but it's an intermitent whining noise coming from the rear of the car that only happens when there's someone in the back seat. Would that be a sensor problem?

[Bruce]

unless you are driving very gently. The mercury switches should stop it from adjusting when you are doing any movement.

If it is adjusting when you are moving it must be doing it when you are stopped.. try to test with your foor OFF the brake....

If it is adjusting too much, I think now the standard problem is accumulators.... although I cant figure out why this would be the case... I have new accumulators in the mail. I will post results in a coupla weeks when they are intsalled.

Bruce

[tdhardin]

I took it out and lowered it with h&r springs and bilstien sports all around. 750 bushings up front and the car was simply perfect.
sooooo much fun. I beat 88m3's in a auto cross in burlington VT ]with it.
Damion