[aaronwpi]

I'm a first time bimmer owner and bought a 2010 328i with xDrive from a user car dealership with after market lowering springs. The car can't clear most speed bumps and it bottoms out over slight declines or bumps on the highway. I think my only option is to bring the suspension back to stock height. The bottoming out is so bad that the headlight leveling arm had bent and is broken in the lowered position. The dealership will fix the headlight but only after I fix the suspension on my own dime.

The car has the m sports package so it is lower than most 3 series. Before I pay a mechanic to put OEM springs back in the car, do you think putting stock springs to bring it back to stock height will fix the bottom out issues and clearing standard speed bumps?

[ajsalida]

Couple of points here. There is no such thing as an xdrive sport suspension. There is only one xdrive suspension and unfortunately it sucks. The springs are too stiff, the ride height is too tall, the shocks are too soft, and with the run flats it also bottoms out very often. I think you will not be pleased going back to Xdrive OEM springs.

A good inexpensive solution is to find a used set of OEM ZSP non-XI sport springs and swap them in. They give a moderately lower than stock ride height, adequate ground clearance, and when coupled with proper length bump stops do not bottom out very often.

Xdrive is one of BMW's worst suspensions ever. Lot more about this in the Xdrive section, look for a thread called "i springs on xi" or similar. Xdrive has some unique subtleties as fasr as getting ride height front vs rear correct and no bottoming or other issues.

Also if you know the make of the aftermarket springs that would help. H&R Sport notorious for being too stiff, H&R Race too stiff and too low. Eibach pro-kit is about same rate as OEM ZSP but no xdrive, and when non Xdrive used rear drop is too low vs front. Etc etc.

[aaronwpi]

Great feedback. My thought was that even after putting OEM springs back in the car I may have the same bottoming out issue even though it is raised back up a half inch. Unknown the type of springs installed. I had BMW check out the car and their recommendation was to bring it back to stock height to fix bottoming out.

The dealership didn't have the make of the after market springs nor could BMW identify (nor did I ask them to).

[ajsalida]

If it is low enough to bottom out a lot I guarantee it is not 1/2 inch lower than stock. IOW putting stock XI springs back in will raise it more like 2" or more. Just compare to a stock XI on a dealer lot side by side, or heck a parking lot somewhere.

[zero2sixtyZ]

Pics?

[Scrippy]

Get a set of good coilovers with adjustable dampening. You can choose height and stiffness this way. It'll take you a good day.