Front wheel rubbing... Why?

[Grush]

Today something very strange happend with the car, and I have no idea of what is going on. I was doing my maneuveurs in the parking lot to park the car at my office, when I hear this strange noise.

It was the front driver's wheel rubing at turns. The car was very inclined to it's side as well. I wondered "wtf, is that my suspension dying?" The difference between left wheel from right wheel was huge.

Well, I was late for work and left the car there. I pretty much always drive on S mode (EDC). Before locking the car, I turned on P mode. Engine wasn't running.

When I came back, the "lack of gap" was gone, and the car seemed ok. Neither way, I took the car to the wheel shop. They do suspention work there as well. On the way there, I turned on S mode. When I got to the shop, car was gapless again, and the wheel was rubbing again on turns.

Well, I went back to work, and the car is at the shop right now. They told me they wanted to plug the car on the computer to see what was going on, but I don't think that anything eletronic was the cause of it (no EDC warning at the dashboard), and there is a charge for that as well. So I told them try to figure it out everything they can without pluging it to the computer.

Never heard of a problem like that. When a EDC strut fails, there is a leakage at the piston and the car just "slams" on every bump, but still the coils should hold the car for a while enough to avoid wheel rubbing... and we have a SLS, but it's only on the rears. Any ideas here?

Had to cancel my beach trip today... :(

[CleanE34]

broken strut? time for coilovers.

[cdnalpina]

Agreed on the coil overs.

I did an experiement with a buddy of mine on a set of E31 EDC struts. Well, we tore them apart to understand how they work. The reason we did this was because his car had the bounciest ass in the world over bumps - like you were riding at the back of the school bus. The accumulators were ok so the strut was the culprit.

There are two solenoids in the strut that open and close to regulate the ride of the car. It seemed that behind each solenoid was a reservoir, one was slightly bigger than the other. How the strut seems to work is that it will fire one of the solenoids to open to allow fluid to move back and forth from the reservoir to the strut. The bigger reservoir for the Komfort and the smaller for the Sport. This gives the varied ride stiffness between the two settings. When the EDC controller senses a problem (or fails) it defaults to hard - both solenoids closed, hence the rough ride.

So what we did was figure out what combinations of wires cause what solenoids to fire. We first tried with both solenoids open and the ride was disgustingly soft - like being in an old caddy. Once we got the right combination of wires, the ride sorted out but his struts leaked out and had to be replaced with coil overs (new EDC and LAD struts are $1200 EACH on RealOEM so imagine what they would be at a stealer!!!).

My guess would be that there is an issue with your controller or the solenoid in the strut itself has failed Likely you are getting the situation that both solenoids are open, allowing as much fluid as possible to go into the reservoirs. Pull the wheel and check also if the strut is leaking. My guess would be the solenoids as that was the culprit in my friend's car (no you can't replace them).

My humble opinion, ditch the EDC. It is a nice feature (when it works) but it is mega bucks when they fail. If you REALLY want EDC, do not buy used - who knows how much life it will have in it still.

Hope that helps...

[Grush]

WoW VERY NICE post. Ty!

I've readed a lot about EDC in my car. Everything that apeared in the M5boards as well. Just to see if it was worthy to maintain the EDC (replace, repair whatever).

I've decided to maintain it, and buy the replacement parts (as well with some 8 series front steering parts) in the next year. I know that would be very expensive (with all of that custom taxes), but it was going to be "affordable" somehow... in the next year... The ride is begginning to get harsh now, but still is driveable (only the steering problems freaks me out sometimes over bumps... right front wheel is very "loose"). I could live with that until then.

But today things got different. IF this problem dosen't gets solved, I'll have to raise some budget (who knows from where), and fix all of these parts. And I'll prolly remove the EDC to cut costs. Don't know about the SLS though.

Oh shit.

I'll have some news in the end of the day. ehhe.

BTW, only my rear strut is leaking right now. Front strut is clean. And i realy don't know why the car is dropping. front EDC affects height as well?!!?? It shouldn't, right? not that much. fackkk!

[CleanE34]

whats the tire size? for 18s you should run 35-40 side profile, for 17s you can run up to 45.

[Grush]

Nothing related to tire profile. They are with the stock measures 245-40 R18.

Left side only is very low. Right side is ok. The ride is dropping in that side.

I'll upload some pics when I get home.

[cdnalpina]

In my Biturbo and my 525i turbo, the previous owners put in Bilsteins and eibachs all around. Eliminated the SLS and EDC. In my humble opinion, it is a better setup if you like spirited driving. The other part is that it is cheaper than replacing OEM struts. If you plan on keeping the car for a while and blow a strut in the future - waaaaay cheaper to replace. My two cents...

[Binjammin]

I didn't realize EDC did anything with the front struts.

[Grush]

Neither did I.

Here are the pics:

Rubbing drivers side wheel.

http://farm4.static.flickr.com/3229/3048599293_9284eb166d.jpg?v=0

little dropped car (right side of the pic)

http://farm4.static.flickr.com/3278/3048598691_8f8bca0038.jpg?v=0

normal passenger side wheel.

http://farm4.static.flickr.com/3146/3049438706_d5d5432dfd.jpg?v=0


UPDATE: car when back to normal, in both modes. WTF. :shifty

so far so good.