Ducati Monster Forum

Kitchen Sink => No Moto Content => Topic started by: Speeddog on February 22, 2010, 07:31:32 PM

Title: Any BMW Techs here?
Post by: Speeddog on February 22, 2010, 07:31:32 PM
My girl's got an '05 Z4 with the dreaded 'sticky steering' issue.

Looking for a DIY solution, or at least a reasonable cost solution.
Title: Re: Any BMW Techs here?
Post by: pigmy on February 23, 2010, 12:57:21 AM

gday nick,ive got a bmw m3 95 model that had similar symptoms.i found two things.first under the steering wheel of my car is a plastic
              bearing assembly which i replaced.but the symptoms still continued to a lesser degree.immediately behind the firewall where
              the steering arm protrudes into engine bay ,you might find it very close to exhaust.this part of the assembly drys out and just
              may need a good lube.it worked for me.hope this helps.if not try a search on bimmerfest and bimmerforum.....cheers pigmy
Title: Re: Any BMW Techs here?
Post by: Speeddog on February 23, 2010, 07:29:07 AM
pigmy, thanks.  :)

I'm not 100% sure, but I think
I've checked on bimmerfest and bimmerforum, seems like replacing the whole steering column and rack is the usual solution.  :P
Title: Re: Any BMW Techs here?
Post by: ducpainter on February 23, 2010, 12:05:13 PM
Quote from: Speeddog on February 23, 2010, 07:29:07 AM
pigmy, thanks.  :)

I'm not 100% sure, but I think
I've checked on bimmerfest and bimmerforum, seems like replacing the whole steering column and rack is the usual solution.  :P
For the BMW shop...

or the DIYer? ;)
Title: Re: Any BMW Techs here?
Post by: Speeddog on February 23, 2010, 01:12:29 PM
Quote from: ducpainter on February 23, 2010, 12:05:13 PM
For the BMW shop...

or the DIYer? ;)

For the shop.

Nobody's fessed up to a DIY.
Seems it's only been warranty, out of pocket at a shop, or 'live with it'.
And the warranty & out of pocket at a shop have been at minimum a steering column replacement.
New price is ~$2.5k.
Used is $550 and up, of course, no idea if used unit is any good at all.

This is an electric power steering setup.
Title: Re: Any BMW Techs here?
Post by: caperix on February 23, 2010, 01:33:31 PM
The motor for the electric power steering is integrated into the upper steering column.  Not aware of any cheap fixes, but do make sure your charging system is working properly as I have seen low alternator output cause stiff steering at idle.
Title: Re: Any BMW Techs here?
Post by: Speeddog on February 23, 2010, 01:57:56 PM
Steering is sticky at all engine speeds.

Stickyness is dependent on interior temperature, when it's cold, it's fine.
When the interior gets warmer, it gets sticky.
Title: Re: Any BMW Techs here?
Post by: capt steubing on February 24, 2010, 08:36:28 AM
Just have your chick do some chin-ups, and a few curls, problem solved! ;D [beer]
Title: Re: Any BMW Techs here?
Post by: mitt on February 24, 2010, 09:59:58 AM
Quote from: Speeddog on February 23, 2010, 01:57:56 PM
Steering is sticky at all engine speeds.

Stickyness is dependent on interior temperature, when it's cold, it's fine.
When the interior gets warmer, it gets sticky.

Seems like the warmth might be expanding a part that is causing mechanical interference some how? 

mitt
Title: Re: Any BMW Techs here?
Post by: Speeddog on February 24, 2010, 11:24:21 AM
Quote from: mitt on February 24, 2010, 09:59:58 AM
Seems like the warmth might be expanding a part that is causing mechanical interference some how? 

mitt

Given the rather small temperature changes involved, IMO it's got to be a plastic bushing that's expanding enough to bind it up.

If the used ones were cheaper, I'd get one and crack it open to try and find the issue.



Title: Re: Any BMW Techs here?
Post by: caperix on February 24, 2010, 01:36:28 PM
How much does it stick?  Does it "break free" once the wheel is turned some or is it always stiff?  Is the "EPS", steering light on in the dash?   There are some plastic bushings at the firewall, though those usually just produce a noise when they stick.
Title: Re: Any BMW Techs here?
Post by: Speeddog on February 24, 2010, 01:48:00 PM
It is sticky, then breaks free, then sticks again.
Can't really drive straight, it's a constant series of over-corrections to each side.
Very fatiguing and annoying.

Don't recall seeing an EPS light on in the dash.
Title: Re: Any BMW Techs here?
Post by: mitt on February 25, 2010, 06:39:39 AM
Quote from: Speeddog on February 24, 2010, 01:48:00 PM
It is sticky, then breaks free, then sticks again.
Can't really drive straight, it's a constant series of over-corrections to each side.
Very fatiguing and annoying.

Don't recall seeing an EPS light on in the dash.

I have seen plastic to plastic rotary parts have this exact behavior in my design work.  The initial resin rich smooth surface finish wears out, and a slightly rougher surface of fillers / fibers emerges, and is like having sand paper to sand paper friction (not that extreme of course).  I have seen it get so bad, that eventually the parts "plastic weld", or lock together after enough rotary operations, and are basically rendered useless.

The solution I have implemented is using a plastic safe grease on the rotary interface, and bingo, the problem went away.  That was applying grease to new parts, then retesting of course, not trying to retro fix a problem assembly. 

Not sure you can apply this experience, but good luck.  I can see it would be annoying as h3ll having a stick stick stick when you are trying to keep the wheel straight with little corrections.

mitt
Title: Re: Any BMW Techs here?
Post by: teddy037.2 on February 25, 2010, 11:11:24 AM
where's mac900?

he fixes bimmers for a living  [thumbsup]
Title: Re: Any BMW Techs here?
Post by: Howie on February 25, 2010, 12:17:47 PM
Speeddog, have you spoken to some dealers about this problem?  It sounds alot like possible NHTSA recall fodder,  "Binding steering may lead to a loss of ability of the driver to change direction of the vehicle and cause a crash, possibly injuring or killing diver and passengers".  There might be a "customer good will" policy on this.
Title: Re: Any BMW Techs here?
Post by: caperix on February 25, 2010, 01:10:05 PM
My best guess with what you are describing is that the steering torque sensor is not reading properly.  The whole column with motor has to be repalced to repalce this sensor.  Depending on milage you may get lucky and be able to get the dealer to goodwill the replacement.
Title: Re: Any BMW Techs here?
Post by: 1KDS on February 25, 2010, 03:12:33 PM
especially right now with all the toyota stuff going on, I'm sure OEMs are scared as hell.
Title: Re: Any BMW Techs here?
Post by: Speeddog on February 25, 2010, 03:21:02 PM
Haven't spoken to any dealers, still in 'research' mode.

I want to have all my info straight before I start leaning on anyone.

@caperix, are you a BMW tech, or.....
Title: Re: Any BMW Techs here?
Post by: caperix on February 26, 2010, 01:22:45 PM
Quote from: Speeddog on February 25, 2010, 03:21:02 PM
Haven't spoken to any dealers, still in 'research' mode.

I want to have all my info straight before I start leaning on anyone.

@caperix, are you a BMW tech, or.....

Yes I am a certified BMW tech, I have seen very few problems with the electric power steering on the the z4's. 
Title: Re: Any BMW Techs here?
Post by: Speeddog on February 26, 2010, 01:33:35 PM
Quote from: caperix on February 26, 2010, 01:22:45 PM
Yes I am a certified BMW tech, I have seen very few problems with the electric power steering on the the z4's. 

Thanks for your input.  [beer]