BMW e90 loose steering feel

weekaizer

I bought a 320d 2 months ago and I'm having issues with the car since I swapped my 17" alloys/Tyres to 18" mv3 with run flat Tyres.. The car feels twitchy at the front, it gets worse as I drive over uneven surfaces, the steering wheel seems to be getting pulled out of my hand as I go over the uneven road.. I've already had 4 wheel laser alignment done which hasn't improved the problem.. Im wondering has anyone ever experienced this problem and what would likely be the problem?. I should also add the steering wheel feels alot heavier than the 2008 320d i used to own. could it possibly be a steering pump/rack issue?? Thanks.

bazz26

Did you try putting the 17" wheels back on and seeing if you have the same issue?

weekaizer

bazz26 wrote: »

Did you try putting the 17" wheels back on and seeing if you have the same issue?

I traded the old alloys when I bought the 18s, Im unsure if the issue is with the wheels, or if the heavier 18s are just exacerbating the problem with the car, either way the problem started when I fitted the new Wheels. there is definitely no previous damage on the wheels I bought...Tyres have 6mm tread left on each... Original BMW wheels that are seen on many e90 bmws so I assume offset is not an issue... Is it possible the suspension geometry would need to be adjusted to suit run flat Tyres??.

bazz26

I'd first try getting it re-aligned by someone who is familiar with doing BMWs.

Wheelnut

It's the runflat tyres and nothing else.

Some brands of runflat are worse than others but they are all horrible.

My E90 came with Continental runflats and they were dangerous. Any drive on a bumpy road was a continuous fight with the steering wheel. Bumps would cause the front to hop sideways and I never knew whether it would go left or right. Sometimes the wheels would get into a certain resonance and the whole car would drift sideways.

Eventually I found Kumho runflats. Their behaviour is almost as good as conventional tyre and cost about 2/3rds the price of Continentals. I've been using them since I discovered them and I have not experimented with any others.

BTW: my car is on 225/45/17s.

mickdw

Dump the run flats would be my advice too. Running 18" wheels on uneven roads is enough of a challenge without having runflats on them.

weekaizer

I'm running bridgestone potenza run flats on the new 18s, (the 17s were also bridgestone but they wernt run flats) my old 320d edition had Michelin super sports and they were exceptionally good on that car, I know how a m sport 320d should handle... Mine is just not in the same ball park ATM..

corkgsxr

Sidewalls of runflats are normally much harder and combined with low profile tires they make cars quite twitchy and theres nothing but the suspension to absorb the imperfections in the road

Wheelnut

weekaizer wrote: »

I'm running bridgestone potenza run flats on the new 18s..

Bridgestone runflats seem to be regarded as just as bad as Continentals, just Google "BMW runflat" or similar and brace yourself for the avalanche.

kerten

It sounds like tramlining due to wider tyres than before.

I bought a e46 with 18" 225/45/18 tyres once and it was continuous fight with steering wheel on uneven roads.

Some tyres are less prone to this than others as far as I read.

eddiem74

corkgsxr wrote: »

Sidewalls of runflats are normally much harder and combined with low profile tires they make cars quite twitchy and theres nothing but the suspension to absorb the imperfections in the road

Wheelnut wrote: »

Bridgestone runflats seem to be regarded as just as bad as Continentals, just Google "BMW runflat" or similar and brace yourself for the avalanche.

+1 on the above speaking from experience. Get rid of the runflats.

Anan1

We have a 320d in the family for 6 years and 130k kms on both Continental and Goodyear runflats, and it's never been the slightest bit twitchy.

corkgsxr

Anan1 wrote: »

We have a 320d in the family for 6 years and 130k kms on both Continental and Goodyear runflats, and it's never been the slightest bit twitchy.

What tire size

Anan1

corkgsxr wrote: »

What tire size

205/55 16. It's a little on the firm side, but it's quiet, grippy and stable.

166man

Anan1 wrote: »

We have a 320d in the family for 6 years and 130k kms on both Continental and Goodyear runflats, and it's never been the slightest bit twitchy.

Well seeing as its running 16's its hardly comparing like with like. OP is 18's, there's a good difference there to be fair.

Anan1

166man wrote: »

Well seeing as its running 16's its hardly comparing like with like. OP is 18's, there's a good difference there to be fair.

My point is that runflats aren't necessarily a problem. Although putting 18"s on a 320d makes little enough sense to me.

corkgsxr

Anan1 wrote: »

205/55 16. It's a little on the firm side, but it's quiet, grippy and stable.

Ya big difference between them and the likes of 225/45/18

You have what the car was designed for.


Its like herselfs hyundai coupe has 225/45/17. Thats the standard fitment. But it was designed for a 3.0 v6. But the 1.6 is a light car so it ends up twitchy when pushed on.

Saying that it had ludicrous corner grip and combined with the ebc pads and bridgestone pozenzas it has the best brakes ever tried. It trys to pull your face off :pac:

MetzgerMeister

Anan1 wrote: »

My point is that runflats aren't necessarily a problem. Although putting 18"s on a 320d makes little enough sense to me.

They most certainly are a problem. I had them on my 335i and coupled with M-Sport suspension and Irish roads, the car used hop along at times and tramlining was a danger, especially with oncoming traffic. I got them looked at and I was told that there was loads of tread left on them and they shouldn't have been tramlining but that's the nature of the reinforced side walls.

When I swapped them for Goodyear Eagle F1s, the steering got a bit heavier, the whole car felt grippier and the same roads aren't a problem now.

Anan1

MetzgerMeister wrote: »

They most certainly are a problem. I had them on my 335i and coupled with M-Sport suspension and Irish roads, the car used hop along at times and tramlining was a danger, especially with oncoming traffic. I got them looked at and I was told that there was loads of tread left on them and they shouldn't have been tramlining but that's the nature of the reinforced side walls.

When I swapped them for Goodyear Eagle F1s, the steering got a bit heavier, the whole car felt grippier and the same roads aren't a problem now.

Maybe they just don't work with 18" wheels and M sport suspension?

weekaizer

Anan1 wrote: »

My point is that runflats aren't necessarily a problem. Although putting 18"s on a 320d makes little enough sense to me.

Eh they come as standard on most m sport 320ds, in fact 19 inch were also optional on the coupe versions. They look far better than 17s..
Also on my previous 2008 320d the 18s with run flat michelins handled absolutely brilliantly..

weekaizer

kerten wrote: »

It sounds like tramlining due to wider tyres than before.

Actually the tire widths are the same, 225 front 255 rear, just much lower and stiffer profile !

Anan1

weekaizer wrote: »

Eh they come as standard on most m sport 320ds, in fact 19 inch were also optional on the coupe versions. They look far better than 17s..

But the ride is awful. Pretty wheels are nice and all that, but IMO it's more important that they do their job well.

weekaizer wrote: »

Also on my previous 2008 320d the 18s with run flat michelins handled absolutely brilliantly..

Given that this problem wasn't there on the old wheels, you'd have to suspect that there's something wrong with one or more of the new set.

weekaizer

Anan1 wrote: »

But the ride is awful. Pretty wheels are nice and all that, but IMO it's more important that they do their job well.
Given that this problem wasn't there on the old wheels, you'd have to suspect that there's something wrong with one or more of the new set.

That's what I'm trying to figure out!
I'm thinking it is the run flats, if I replaced them, how much could I get if I sold them on ?

Anan1

weekaizer wrote: »

That's what I'm trying to figure out!
I'm thinking it is the run flats, if I replaced them, how much could I get if I sold them on ?

Thing is, it might be the wheels themselves. I take it you've had them balanced? Have you tried swapping them front to rear?

Paddy@CIRL

It's probably a combination of Run Flats & a staggered setup if the car is aligned properly.

weekaizer

Anan1 wrote: »

Thing is, it might be the wheels themselves. I take it you've had them balanced? Have you tried swapping them front to rear?

Haven't had them balanced but there's no vibration, I can't swap front to rear because the rear wheels are wider and setup would be terribly wrong!

bazz26

I had 18" run flats on my old E90 M Sport and replaced them with non run flats. The non run flats definitely improved the ride but I never felt the run flats were a problem in the 12 months I drove them before replacing then with standard tyres. Mine came from the factory with an 18" staggered set up.

weekaizer

bazz26 wrote: »

I had 18" run flats on my old E90 M Sport and replaced them with non run flats. The non run flats definitely improved the ride but I never felt the run flats were a problem in the 12 months I drove them before replacing then with standard tyres. Mine came from the factory with an 18" staggered set up.

I have to say the run flat Michelin sports I had on were excellent, no twitchyness and great grip but I guess the bridgestone run flats are not as good as the michelins... So I guess option A is change the run flats to non run flats balance the wheels and hopefully sell the run flats, If that doesn't work, option B is get the steering pump/rack/bushings/geometry looked at...option C sell the fupping car!