[850tgul]

Hello,

I've just picked up a '17 330xi for my commuter car. PPI results showed a leaking front strut. The car has 100k miles.

I plan to replace, not necessarily upgrade, both front struts and was looking for confirmation on the correct struts to use.

The car has the S7AC sport line option but not the adaptive m-sport suspension.

I was thinking the Bilstein "Touring", rather than the Bilstein "Performance", strut would be appropriate but was hoping the F30 gurus could chime in.

These struts, along with the Lemforder front strut mount kit, was what I was eyeing. Thx

https://www.fcpeuro.com/products/bmw...n-bil-22238269

[cfm56d7b]

If the car has 100K miles, replacing all four struts + springs might be a better option especially if the rear struts may fail in the near future. This is also a good time to perform 4 wheel alignment.

Koni Special Active struts are worth exploring as an alternative to OEM struts or Bilstein B4 struts which are 10% stiffer than OEM.

While installing new struts, ask the shop to inspect all suspension parts with rubber bushings due to high mileage.

Helpful thread to read https://f30.bimmerpost.com/forums/sh....php?t=1675667 while acknowledging johnung contributions.

[850tgul]

Originally Posted by cfm56d7b

If the car has 100K miles, replacing all four struts + springs might be a better option especially if the rear struts may fail in the near future. This is also a good time to perform 4 wheel alignment.

Koni Special Active struts are worth exploring as an alternative to OEM struts or Bilstein B4 struts which are 10% stiffer than OEM.

While installing new struts, ask the shop to inspect all suspension parts with rubber bushings due to high mileage.

Helpful thread to read https://f30.bimmerpost.com/forums/sh....php?t=1675667 while acknowledging johnung contributions.

Thank you.

I had a PPI performed and the entire car was inspected, the only things noted were brake pads and one front strut leaking.

After seeing how easy the rears are to swap, I do think the I will swap those out as well. An alignment will certainly be done afterwards.

Are the springs known to fail after 100k on the F30s? I had springs fail prematurely on an E46 M3 years go, so I suppose not too shocking.

[johnung]

Originally Posted by 850tgul

Thank you.

I had a PPI performed and the entire car was inspected, the only things noted were brake pads and one front strut leaking.

After seeing how easy the rears are to swap, I do think the I will swap those out as well. An alignment will certainly be done afterwards.

Are the springs known to fail after 100k on the F30s? I had springs fail prematurely on an E46 M3 years go, so I suppose not too shocking.

I wouldn’t say that springs are prone to fail but worth changing when dampers are being done. IMO Eibach is the best choice. See photo for part number.

At 100k miles definitely replace suspension top hats and rubber bits like spring perches to make it ride like new. FCP Euro is a good source.

Highly recommend Hawk 5.0 brake pads

Enjoy your new car!

[cfm56d7b]

Originally Posted by 850tgul

Thank you.

I had a PPI performed and the entire car was inspected, the only things noted were brake pads and one front strut leaking.

After seeing how easy the rears are to swap, I do think the I will swap those out as well. An alignment will certainly be done afterwards.

Are the springs known to fail after 100k on the F30s? I had springs fail prematurely on an E46 M3 years go, so I suppose not too shocking.

At 100K miles, matching new struts with new springs has many benefits:

- Avoid additional labor costs when springs do fail
- High mileage springs and new struts isn’t a helpful combination because as the springs get older the spring oscillation behavior is not the same and can impact the struts performance. Springs are inexpensive.

Enjoy the refreshed suspension!

[850tgul]

Originally Posted by cfm56d7b

At 100K miles, matching new struts with new springs has many benefits:

- Avoid additional labor costs when springs do fail
- High mileage springs and new struts isn’t a helpful combination because as the springs get older the spring oscillation behavior is not the same and can impact the struts performance. Springs are inexpensive.

Enjoy the refreshed suspension!

I see that aftermarket springs are inexpensive but they all seem to add stiffness and lower the car from stock, both of which I'd rather not do.

OEM springs from BMW are NOT inexpensive and not sure I have the luxury to wait around for a low mileage set of OEM 330xi springs to pop up in the classifieds.

Are there any inexpensive OEM-like springs out there which don't lower or stiffen up the car?

Thanks

[johnung]

Originally Posted by 850tgul

I see that aftermarket springs are inexpensive but they all seem to add stiffness and lower the car from stock, both of which I'd rather not do.

OEM springs from BMW are NOT inexpensive and not sure I have the luxury to wait around for a low mileage set of OEM 330xi springs to pop up in the classifieds.

Are there any inexpensive OEM-like springs out there which don't lower or stiffen up the car?

Thanks

The Eibach Spring Kit that i suggested is a very mild lowering of 0.8” in front and 0.6” in the rear. It eliminates some the excess tire/fender gap and improves handling. Unlike other springs that can be stiff/harsh with 50% or more increases in spring rates, Eibach spring kit rates are roughly 10% more which improves control without being detrimental to ride.

If you are dead set on the stock height, Eibach has recently introduced stock replacement springs. Not sure how available they are yet in the US. I’ve used an excellent German retailer for many years who ships to the US. His email is spelled out below:
Andreas DOT Schade AT gmx DOT de

Link to Eibach German Catalog that shows individual springs in their spring kit as well as part numbers for their individual stock springs.

https://web2.carparts-cat.com/defaul...04&14=4&12=130

BMW uses a variety of springs which are determined at the factory based on a car’s optional equipment which can weigh differently. The stock spring part numbers are NOT easy to look up based on VIN. The only way to tell for sure which stock springs came on a car is to find the white tag on the spring itself and find the two letter code on it, such as AF, BH, etc. Codes are listed in some BMW database that no dealers and no one seems to have.

Don’t worry about any of that. Eibach has already done the research. What you need to do is to enter your full VIN into the mdecoder website to get a line item printout of the packages installed on your car, especially whether it has the S2VF code for the Adaptive/EDC suspension. (If you see “A” at the end that just indicates a car made for North America- ignore the A)

See photos for how to interpret the Eibach stock spring choices. Standard or Adaptive dampers is the key. Remember that this stuff is written by engineers and then translated from German to English. So don’t get caught up with references to things like tow bars, etc.

Hope this helps!

[850tgul]

Originally Posted by johnung

The Eibach Spring Kit that i suggested is a very mild lowering of 0.8” in front and 0.6” in the rear. It eliminates some the excess tire/fender gap and improves handling. Unlike other springs that can be stiff/harsh with 50% or more increases in spring rates, Eibach spring kit rates are roughly 10% more which improves control without being detrimental to ride.

If you are dead set on the stock height, Eibach has recently introduced stock replacement springs. Not sure how available they are yet in the US. I’ve used an excellent German retailer for many years who ships to the US. His email is spelled out below:
Andreas DOT Schade AT gmx DOT de

Link to Eibach German Catalog that shows individual springs in their spring kit as well as part numbers for their individual stock springs.

https://web2.carparts-cat.com/defaul...04&14=4&12=130

BMW uses a variety of springs which are determined at the factory based on a car’s optional equipment which can weigh differently. The stock spring part numbers are NOT easy to look up based on VIN. The only way to tell for sure which stock springs came on a car is to find the white tag on the spring itself and find the two letter code on it, such as AF, BH, etc. Codes are listed in some BMW database that no dealers and no one seems to have.

Don’t worry about any of that. Eibach has already done the research. What you need to do is to enter your full VIN into the mdecoder website to get a line item printout of the packages installed on your car, especially whether it has the S2VF code for the Adaptive/EDC suspension. (If you see “A” at the end that just indicates a car made for North America- ignore the A)

See photos for how to interpret the Eibach stock spring choices. Standard or Adaptive dampers is the key. Remember that this stuff is written by engineers and then translated from German to English. So don’t get caught up with references to things like tow bars, etc.

Hope this helps!

Great info, johnung, thank you very much!

[casualDIYer]

Originally Posted by cfm56d7b

If the car has 100K miles, replacing all four struts + springs might be a better option especially if the rear struts may fail in the near future. This is also a good time to perform 4 wheel alignment.

+1

In addition to dampers rubber-derived parts will fail not only over distance but time as well. The chemical bonds that make such parts soft and pliable break down over time as they are exposed to heat and cold, which given the location of suspension parts is quite often. While there are sprays that can temporarily revive the break down often the repair is short lived. Doing a suspension swap/refresh? Swap out top hats, spring perches, end links, and even control arms if they are showing end of life wear.