Soft floaty suspension
Discussion
I have a 2011 328i with the base suspension and as the title suggests when I am driving on the freeway it feels like the suspension floats left and right. It is also pretty soft and tends to bounce on bigger bumps. It does usually settle down a bit if you are pushing it through a corner. Does anyone else with the base suspension have this same problem? I only have about 50k miles so far.
Yes, I had this problem with my 2010 320d. Assuming your tyres pressures are ok, there are probably two contributing factors:
1) With the E90 LCI, I think that (from the cars I’ve driven, I’ve not heard an official BMW statement) both SE and M Sport got softer. SE became way too soft for me. It appeared (again, just talking from experience here) to happen again for the F30, making the SE's suspension laughably soft and uncontrolled (imho, obviously thousands disagree!).
2) As all cars age, dampers will wear out. The damper controls the movement of the spring, so as they wear you get more ‘bounce’ to put it simply. You’ll notice at 20-30k miles, and for me at least it becomes a real problem beyond about 70-100k miles (the big range is because it depends on the type of driving). ETA: I see you've only done 50k miles. If those miles were hard on the dampers, they may be the problem. You won't know till you change them though, and if they don't fix it that's money wasted. You can also get faulty dampers on new cars - I've seen it on one of my BMWs.
Bushes also wear, but I don’t think this is your problem. They make the car feel less 'precise' when they age.
There’s another factor, but this may or may not apply to your car: tyres. The tyre sidewall is an undamped spring, and suspension is always designed around a particular tyre. Most non-M BMWs are designed for run flats, so if you’ve put non RFTs on the car it’ll make the suspension bouncier, because you've effectively reduced the spring rate of a component in the system to something different from when the factory set everything up. People normally advise others to ditch RFTs, but this actually depends on the tyre in question. BMW usually maintain rolling circumference with different wheel options, so this results in smaller sidewalls for bigger wheels and bigger sidewalls for smaller wheels. In the latter case, as with my 205/55/16 tyres, non RFTs turn my car into a bouncy castle. If you start with a tiny sidewall, like a 255/35, you may find non-RFTs are a relief, so for tyres it just depends.
My solution was a Birds suspension kit, and then RFTs made a further improvement (as above, due to my tyres’ huge sidewalls). My car now drives beautifully, and I don’t use that word lightly. BMW won’t sell you M Sport suspension for an SE car, but if you give them someone else’s VIN (from an M Sport car) they will, but the kit is more expensive than Birds, which is why I just went for Birds.
1) With the E90 LCI, I think that (from the cars I’ve driven, I’ve not heard an official BMW statement) both SE and M Sport got softer. SE became way too soft for me. It appeared (again, just talking from experience here) to happen again for the F30, making the SE's suspension laughably soft and uncontrolled (imho, obviously thousands disagree!).
2) As all cars age, dampers will wear out. The damper controls the movement of the spring, so as they wear you get more ‘bounce’ to put it simply. You’ll notice at 20-30k miles, and for me at least it becomes a real problem beyond about 70-100k miles (the big range is because it depends on the type of driving). ETA: I see you've only done 50k miles. If those miles were hard on the dampers, they may be the problem. You won't know till you change them though, and if they don't fix it that's money wasted. You can also get faulty dampers on new cars - I've seen it on one of my BMWs.
Bushes also wear, but I don’t think this is your problem. They make the car feel less 'precise' when they age.
There’s another factor, but this may or may not apply to your car: tyres. The tyre sidewall is an undamped spring, and suspension is always designed around a particular tyre. Most non-M BMWs are designed for run flats, so if you’ve put non RFTs on the car it’ll make the suspension bouncier, because you've effectively reduced the spring rate of a component in the system to something different from when the factory set everything up. People normally advise others to ditch RFTs, but this actually depends on the tyre in question. BMW usually maintain rolling circumference with different wheel options, so this results in smaller sidewalls for bigger wheels and bigger sidewalls for smaller wheels. In the latter case, as with my 205/55/16 tyres, non RFTs turn my car into a bouncy castle. If you start with a tiny sidewall, like a 255/35, you may find non-RFTs are a relief, so for tyres it just depends.
My solution was a Birds suspension kit, and then RFTs made a further improvement (as above, due to my tyres’ huge sidewalls). My car now drives beautifully, and I don’t use that word lightly. BMW won’t sell you M Sport suspension for an SE car, but if you give them someone else’s VIN (from an M Sport car) they will, but the kit is more expensive than Birds, which is why I just went for Birds.
Edited by RobM77 on Tuesday 11th June 11:57
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