[scoss]

Notice that the over bumps and dips in the road car is very over reactive and can't keep a straight line. it will lean into the dip or bumps in the road. could this be a tie rod (inner/outer) control arm related?

Anyone else have this. Cars done 69k.

Thanks

[Scott340]

Originally Posted by scoss

Notice that the over bumps and dips in the road car is very over reactive and can't keep a straight line. it will lean into the dip or bumps in the road. could this be a tie rod (inner/outer) control arm related?

Anyone else have this. Cars done 69k.

Thanks

Had a LCI 320d which didn't have adaptive steering and that was fine, even on run flats. Upgraded to a LCI 340i with adaptive steering and it was absolutely horrendous, exactly the same as yours to the point it was dangerous. Took the run flat's off which made a huge difference, but still vague at higher speeds. Dealers said all was fine (obviously!), had it aligned which made no difference, and I couldn't be bothered going through the hassle.

I found the weighted steering in sports mode made the vauge feeling even worse, so turned that off. Other than that I've learned to live with it and got used to it. Only when I get a loan car am I reminded how crap the steering feel is. I've read of people getting mechanical parts changed and it making no difference, so the fact my non adaptive steering LCI 320d was fine makes me wonder whether it's a software issue with adaptive steering spec cars?

[scoss]

Originally Posted by Scott340

Had a LCI 320d which didn't have adaptive steering and that was fine, even on run flats. Upgraded to a LCI 340i with adaptive steering and it was absolutely horrendous, exactly the same as yours to the point it was dangerous. Took the run flat's off which made a huge difference, but still vague at higher speeds. Dealers said all was fine (obviously!), had it aligned which made no difference, and I couldn't be bothered going through the hassle.

I found the weighted steering in sports mode made the vauge feeling even worse, so turned that off. Other than that I've learned to live with it and got used to it. Only when I get a loan car am I reminded how crap the steering feel is. I've read of people getting mechanical parts changed and it making no difference, so the fact my non adaptive steering LCI 320d was fine makes me wonder whether it's a software issue with adaptive steering spec cars?

When you say adaptive so you mean servotronic, the wheel will reduce resistance the slow you go and visa versa when at motorway speeds?

I’ve got the car booked in at my local garage and I’m almost hoping for them to find an issue with it. I’ve got MPS4’s and I’m thinking
Of going back to RFTS just for the hard side wall to firm up the steering feel.

[ade555]

@[scoss] I get the same feel in my 4 series been honest so you not alone, and the faster I drive over poor roads the worse it gets, I took the car to mot place where they put car on shakers to see if there is any play in anything also took to bmw specialist because I couldn't find anything wrong my self and still no wiser, only thing I notice there is slight movement in front thrust arms the one that are oil filled but is very minimal and been told that's how they are, I have no knocks or anything else in suspension, to me the front end don't feel very planted over bumps ect., I personally think if you went back to RFT this would make even worse.

[scoss]

Originally Posted by ade555

@[scoss] I get the same feel in my 4 series been honest so you not alone, and the faster I drive over poor roads the worse it gets, I took the car to mot place where they put car on shakers to see if there is any play in anything also took to bmw specialist because I couldn't find anything wrong my self and still no wiser, only thing I notice there is slight movement in front thrust arms the one that are oil filled but is very minimal and been told that's how they are, I have no knocks or anything else in suspension, to me the front end don't feel very planted over bumps ect., I personally think if you went back to RFT this would make even worse.

I’ve heard quite a few people go back to run flats because they weren’t happy with the softer side wall of the summer tires. They’ve said that the firm attire will definitely sharpens up the steering feel.

[GOF_430d]

It might be psychological, but for me at least, the symptom you are describing occurs when the tyre pressures are lower than normal. This morning the steering felt wooly and a quick check on the tyre pressures via the idrive screen confirmed that the fronts are at 2.2 bar [2.4 bar standard] and 2.5 bar rear [2.7 bar standard]. The reduced pressures are probably related to the cold weather - I last checked and corrected the tyre pressures when it was warmer.

Though I have done 64k and the suspension is certainly softer and the car more wallowy [not sure that's a word] than it was when it was younger - then again so am I, so both the car & I are ageing.

[Ennoch]

Was just about to say what GOF_430d said; tyre pressures. I find with 2.7-2.8 bar cold the steering is decent but as soon as it hits 2.5ish the steering starts to feel wooly. 2.4 and it feels like the steering wheel is no longer connected. Double check your tyre pressures as with the cold suddenly arriving that will have dropped things down noticeably in a short space of time. It might not be the answer to your problem, but it's certainly the cheapest one to check!

[ade555]

Originally Posted by scoss

I’ve heard quite a few people go back to run flats because they weren’t happy with the softer side wall of the summer tires. They’ve said that the firm attire will definitely sharpens up the steering feel.

I'm on 20" wheels with low hard side wall so I'm straggling to believe the above but I could be wrong. I think most of the problem is how bad some of the roads are even A roads, I don't notice nothing wrong on dual and motorways and car is dream to drive so for most of part I just put up with this, I might take a look maybe putting more toe in on front axle to see if will make a bit more stable.

[robbiep]

20" wheels are always going to have terrible tramlining and a tendency to react to any imperfection in the road - no matter whether or not you're running RFTs

[Watsey]

The tension struts (lower control arms) use oil-filled bushes which are renowned for being very soft and hence having a lot of deflection. It's one of the compromises of BMW's strategy to adopt run flat tyres - the increased NVH needs to be isolated.

Having the OEM bushes changed for poly units, or new LCAs with monoballs, makes a substantial improvement to steering precision, control and feel.

[scoss]

Originally Posted by Ennoch

Was just about to say what GOF_430d said; tyre pressures. I find with 2.7-2.8 bar cold the steering is decent but as soon as it hits 2.5ish the steering starts to feel wooly. 2.4 and it feels like the steering wheel is no longer connected. Double check your tyre pressures as with the cold suddenly arriving that will have dropped things down noticeably in a short space of time. It might not be the answer to your problem, but it's certainly the cheapest one to check!

Thanks for the tips. I checked my pressures and the fronts/rears are at 2.3/2.4 so def under. Will up the pressures to see if that’s the issue. I’m sure (fingers crossed) this is the issue.

[ade555]

Originally Posted by Watsey

The tension struts (loser control arms) use oil-filled bushes which are renowned for being very soft and hence having a lot of deflection. It's one of the compromises of BMW's strategy to adopt run flat tyres - the increased NVH needs to be isolated.

Having the OEM bushes changed for poly units, or new LCAs with monoballs, makes a substantial improvement to steering precision, control and feel.

I was surprised how soft they are, out of interest can you get them LCAs with monoballs in UK?

[scoss]

Originally Posted by ade555

I was surprised how soft they are, out of interest can you get them LCAs with monoballs in UK?

Are you referring to control arms with the ball joints built into them as one whole unit? Then yes that’s is the case.

[TankTomF30330i]

Originally Posted by Watsey

The tension struts (lower control arms) use oil-filled bushes which are renowned for being very soft and hence having a lot of deflection. It's one of the compromises of BMW's strategy to adopt run flat tyres - the increased NVH needs to be isolated.

Having the OEM bushes changed for poly units, or new LCAs with monoballs, makes a substantial improvement to steering precision, control and feel.

Hi Watsey, I’ve got a bmw 330i 2017, it’s hit about 86,000 ,I’ve noticed now a loose feel in the wheel while driving, it dosent have a constant feel in the wheel if you know what I mean. in comfort it’s worse but, when I put it in sport the wheel stiffens up but I still notice it. I have had both front left and right adaptive suspension replaced due to leakage and had a few alignments done which haven’t made a difference.

Do you think maybe by replacing the lower control arms with poly units or LCAS with moomballs would fix the problem ?

I’m at a lose at the moment the mechanics have been pretty useless in identifying the problem

Cheers

[TurboWeasel]

The symptoms of the original post were exactly what mine did, and in my case it was down to knackered M sport shocks being the primary cause, and crap tyres being the secondary issue.

Since Bilstein B12 and Pilot Sport 4 run flats it is absolutely rock solid stable.

People often mistake dry damper bodies as fine. Wrong. If all the gas has escaped, they are only 50% efficient, which gets worse and worse with heat as there is nothing to prevent shock oil cavitation over bumps.....hence the squirming and wriggling about on the road.

Check the obvious stuff first. Shocks, tyres, bushes. The stock oil filled thrust bushes are fine and don't cause the OP's symptoms, but aftermarket mono ball arm and urethane bush sellers will obviously tell you they are. Poly has no place on a road car. Well, certainly not a daily one, but a weekend toy, it's borderline acceptable.

Make sure the steering rack tensioning block has been done as well....properly.

[MY340i]

Before you embark on spending silly money on a new rack etc, try changing your tires to bmw star marked or MO tyres.

[TurboWeasel]

That does indeed help. For example, the Pilot Sport 4 BMW * run flats are much better than the generic non-run flat ones, but you will always get a certain amount of straight line fidgeting over uneven surfaces, especially cambered roads for drainage. It's the nature of modern low profile asymmetric tyres.

So long as the steering isn't tugging you all over the shop or is a constant battle keeping it in a straight line, it's normal for these cars.

[davethefish]

have you checked for the steering bush issue?

[TurboWeasel]

Absolutely do the steering rack tensioning block upgrade before anything else

They keep going up in price due to demand. Every Fx car with the Thyssenkrupp rack will need doing at some point. I bought 2 of the kits when they were 50 quid, but now they're £110ish.

Don't use the crappy BMW grease. Use a good synthetic grease like Loctite Superlube and it'll be a one and done job. The OEM petroleum based grease dries out over time and then you get sticky steering off center.

[MY340i]

ZF’s won’t have this sadly.
If ZF it will be around £600 to remove the rack strip, regrease, refit and calibrate