sport suspension or worn out suspension?

[esunarto]

i got a 2007 335i a few months ago, and the suspension is extremely stiff.
Sometimes on rough road, i'm worried that the car might just fall apart.
i don't know if i have a sport suspension, my SA said i do, but doesn't it usually mean staggered wheels? mine is the same front and back, 225/45 r17.
my tires are OEM potenza RFT.
how else can i figure out if mine has a sport suspension?
how stiff is a bmw sport suspension ? i've driven my gf's civic with sport suspension, it's rough, but not THAT rough.
i'm just worried that there's something actually wrong with the suspension.

please help.
Thanks in advance!

[mystreba]

Do you have pics of the car? Doesn't sound like you have the Sport Package with those 17" rims. Based on what your SA said, the suspension was likely modified. In that case it would have been up to the PO to upgrade/stagger the wheels, which they apparently elected not to do.

Car shouldn't be that rough, unless it was a serious mod. I'd grab a flashlight and look up into the front wheel well to see what the coil/strut setup looks like. It should be obvious if it's a mod - bright coils or brand markings of some sort on the strut. If it's really lowered, you may need to pull the wheel to see it. Or you can check under the hood - the mount tower would look different from the stock setup which is fairly non-descript with a small black sway bar, like this -

http://i135.photobucket.com/albums/q121/mystreba/IMG_0900.jpg

What did you drive before this one?

[esunarto]

thanks for the reply! i think the previous owner isn't the racing type, here's the pics from the mount to the spring.
i've driven some regular vehicles, wide range, no real sport car tho.
optima, civic, f150, 328i.
i think the closest ones i've driven should be sport package civic and non-sport 328i. but this one is very noticeably rougher than both.

how would a regular joe tell if there's something wrong with the suspension?

[mystreba]

Definitely stock. Car shouldn't be that rough, but I guess it depends on how rough your roads are. I've got the exact same car and the ride is perfectly smooth, although you definitely feel the road.

It sounds like something is wrong, but it'll take someone way more knowledgable than me to help you diagnose it.

How many miles? Are you hearing noises, or does it just feel rough? All wheels or is it isolated to one area?

[ElRedOne]

Is this your first experience with Run-flat tires? If so, you're feeling the awful ride they provide. Do a search on the myriad discussions concerning their shortcomings and replacement.

[mystreba]

Dunno - mine has RFT and it's a sweet ride. Doesn't account for feeling that the car is going to fall apart, as the OP stated.

[esunarto]

it has 23k miles and it does have RFT which i'm planning to switch soon ( to non-RFT, hopefully to alleviate the problem )
the tires are probably 3/4th worn.

since the factory warranty is coming up, i'm just wondering if i need to push the dealer to check the suspension. my SA would just say it's sport suspension and left it at that.

what is the hallmark of bad / worn suspension or worn struts ?
besides maybe uneven wear on tires?

[floydr]

what is the hallmark of bad / worn suspension or worn struts ? besides maybe uneven wear on tires?

It's highly unlikely that the shocks and CAB's are gone at 23K miles. In BMW's case, you can't really diagnose bad suspension from tire wear, since (in general) BMW's suspension setup actually results in slightly uneven wear - fronts usually wear more at the outer shoulder, rears often at the inner.

I think it's likely that what you are feeling is "somewhat" normal, exacerbated by the 1st generation RFTs, and a suspension that is far stiffer than any Honda (except for an NSX:cool). Go back to the dealer and demand to drive a new 335 i off the lot and see if it's the same - have the SA ride with you as you drive yours and the new one.

[Critter7r]

Best bet is to simply take it to the dealer and have someone go for a test drive with you so that you can point out your concerns. That way, someone that has driven countless BMWs will be able to tell you if there's an issue or if it really is "just the tires"

Also, at 23K, I'd expect that the tires are worn (at least) down to the 2nd half of their life, which could be adding to the harshness of the ride you're feeling.