[rapagonman]

Hello.

Few months ago I performed big repairs on my bmw F30 (front). The following parts were changed:

Struts (3 parts)
Wishbones
Suspension stabilizer bar link

The front end sits still extremely high, and the handling is extremely "loose" especially in higher speed corners.

Few days ago I decided to check my old springs height (they had over 100k miles on them) and they wereonly 280mm, does it sound very low? I havent lowered the car at all, and there was no mention about anything like that when I bought it about a year ago.

The new springs height is 319mm (RA4016 / KYB) and when I've been calling to different service centers about stock springs height, they always say it's 319mm. Is this correct?

Sorry for the confusing post. Please ask more questions if needed!

Edit: My current plan is to test driveability of the car by installing old springs back.

[keithyo88]

Please comment on how the rear of the car feels with the new springs. If they feel a lot better then re-installing the old springs may not be necessary. Are those BMW Dealer Service Centers that you are calling? Sorry I do not know the proscribed height.

[rapagonman]

Rear feels normal, I guess. There was no new parts installed there. The front feels bumpy and "loose".

Actually they were part dealers. One of them focused only on BMW.

[keithyo88]

Sorry for my mistake and being dense. You noted that these were changed:
Struts (3 parts)
Wishbones
Suspension stabilizer bar link
So your question could be re-phrased:
Front end sits high and handles loose
Installed new RA4016 / KYB
Front end still sits high and still handles loose
Plan to re-install original springs to check difference
Unsure if stock spring height is 319mm

[johnung]

Originally Posted by rapagonman

Hello.

Few months ago I performed big repairs on my bmw F30 (front). The following parts were changed:

Struts (3 parts)
Wishbones
Suspension stabilizer bar link

The front end sits still extremely high, and the handling is extremely "loose" especially in higher speed corners.

Few days ago I decided to check my old springs height (they had over 100k miles on them) and they wereonly 280mm, does it sound very low? I havent lowered the car at all, and there was no mention about anything like that when I bought it about a year ago.

The new springs height is 319mm (RA4016 / KYB) and when I've been calling to different service centers about stock springs height, they always say it's 319mm. Is this correct?

Sorry for the confusing post. Please ask more questions if needed!

Edit: My current plan is to test driveability of the car by installing old springs back.

You really can’t just say F30. You need to identify the year, model and RWD or XDrive. The mileage would help too. There are many different factory springs installed on the many iterations of BMW F30’s. You don’t mention if the aftermarket springs that you installed were supposed to lower the car and if so, by how much?

At the factory they installed springs based on axle weight. So the same exact car except one with a sunroof and another without could potentially have different springs.

I can’t recall the procedure for measuring spring height, if it can be done unloaded or if it requires a specific load. If you look at the attached photos they compare the Eibach springs in kit E11-20-031-06-22 to stock springs from my 2015 335i XDrive. The front Eibach lowered the car by 0.8” and the rear by 0.6”. The Eibach spec height for the front is 235mm.

I admire you wanting to make the effort to experiment. IMO swapping back the stock springs isn’t going to provide much information.

Suspensions are complex. Many components overlap in their functions to work together as a system. There could be a number of things causing the symptoms that you mentioned.

With over 100k miles, your front struts and/or rear shocks could be shot and definitely are if they are original. Also, if your front upper control arm (thrust arm) bushing is leaking fluid, that could cause symptoms. That’s fixed by replacing the entire arm which is easy.

It helps to take a baseline height measurement before suspension changes. At all four wheels measure from centerpoint on wheel cap straight up to fender lip and write them down. This only changes if springs change. Wheel/tire changes have no effect.

If you have XDrive, never lower front by >1.5” or you could start snapping front drive shafts.

Hope this helps!

[rapagonman]

Hey. Thanks for the reply. Sorry, the model of my car is F30 ED 2016 lci rwd.

No, the new springs were not installed to lower the car. I just thought switching them same time now would be easy. Since I open everything up when changing shocks.

I don't believe any part from the front is shot -- the car drove well before these repairs.

In a week the old springs will be installed back by a BMW service. They'll tell if there is something else to be changed up front