Steering Issue ( Aquaplaning sensation)

[enuff_zed]

Hi @blunderthumbs can you provide any update? I have a similar issue in my '07 Z4C - 65+ mph the steering wheel goes left and right on its own, like intense tramlining... got an alignment and wheel balance done and it helped nothing. Wondering if you were able to resolve your problem?

Welcome to the forum.
The very first thing you should do is adjust the spacer between the column and the motor. This nearly always cures it and is fairly simple to do, though it can take a couple of goes to move it the right amount.
Whereabouts are you? If not keen to try yourself then there may be someone nearby who can help?

 

[9designs]

Mine has started to have over sensitive in the straight ahead position as well, didn’t do it until took the Bridgestone RF off and fitted Hankook along with an alignment after refreshing all the bushes. So it’s either coincidence of as I’m wondering alignment issues. Like others it has this twitch and self steering effect from around 65, feels to light as well.
I suspect the new tyres have much more feedback and sensitive, feels like too much toe out. I had the opposite on my GR Yaris, so the alignment was updated to give me more toe out, which added feel and improved turn in.
So I gave each tie rod nut half a turn for more toe in. It certainly helped, not 100% but better more of the time.
Plan is to get it on a Hunter and have play with the settings, another 1/4 turn might do it.

 

[gigalith]

Welcome to the forum.
The very first thing you should do is adjust the spacer between the column and the motor. This nearly always cures it and is fairly simple to do, though it can take a couple of goes to move it the right amount.
Whereabouts are you? If not keen to try yourself then there may be someone nearby who can help?

Thanks enuff_zed! I'm all the way in Northern California, but I have an appointment scheduled with a good local BMW mechanic so I'll tell them what you recommended and hope that will fix it. will update here. Really appreciate the advice

 

[enuff_zed]

Welcome to the forum.
The very first thing you should do is adjust the spacer between the column and the motor. This nearly always cures it and is fairly simple to do, though it can take a couple of goes to move it the right amount.
Whereabouts are you? If not keen to try yourself then there may be someone nearby who can help?

Thanks enuff_zed! I'm all the way in Northern California, but I have an appointment scheduled with a good local BMW mechanic so I'll tell them what you recommended and hope that will fix it. will update here. Really appreciate the advice

Ah yes. Just outside my daily travel range

Plenty of info on here but basically all they need to do is loosen the two torx head bolts that hold the motor on. Only just enough to tap the ring round 5-10mm.
Mark the ring and the motor first as a datum point.

Pretty sure the motor is universal to lhd and rhd but not exactly sure about the spacer ring.
In the uk we move the bottom of the ring away from the seat. Whether this is the same or opposite on lhd I’m not sure?

 

[gigalith]

Ah yes. Just outside my daily travel range

I basically told the mechanics exactly what you said (okay I literally emailed them the screenshots of your words) and, they were as grateful as I am for your advice because they hadn't encountered this particular issue before & wouldn't have thought to go through your steps.

I honestly was not sure whether this would fix the problem since I already tried a handful of other things which accomplished little, but yes this has stopped my steering wheel from wandering! Finally I can enjoy my Z4 fully

Really enormous thanks enuff_zed!

 

[enuff_zed]

Ah yes. Just outside my daily travel range

I basically told the mechanics exactly what you said (okay I literally emailed them the screenshots of your words) and, they were as grateful as I am for your advice because they hadn't encountered this particular issue before & wouldn't have thought to go through your steps.

I honestly was not sure whether this would fix the problem since I already tried a handful of other things which accomplished little, but yes this has stopped my steering wheel from wandering! Finally I can enjoy my Z4 fully

Really enormous thanks enuff_zed!

Excellent news. Glad that has fixed it for you, though I’ll be honest I was disappointed when the flight tickets never arrived.

 

[9designs]

Are these the 2 bolts to loosen to adjust the motor? .. can you get access with just the bottom cover off?

 

[enuff_zed]

Are these the 2 bolts to loosen to adjust the motor? .. can you get access with just the bottom cover off?

Yup that's them.
Get the lower cowl off and the foot-well panel, then adjust the column down and back towards you. That gives the best access to the front bolt.
Rear one you can do by feel or if you're lithe enough, get your head in the well and look up.
Only just loosen them a little, and definitely mark a datum point before you start.

 

[9designs]

Okay right, found them but what the heck tool did you get to them with, looks like E10, 3/8 drive to big, I only go up to E8 on 1/4…. Looks like i need a Torx spanner/wrench ?

 

[enuff_zed]

Okay right, found them but what the heck tool did you get to them with, looks like E10, 3/8 drive to big, I only go up to E8 on 1/4…. Looks like i need a Torx spanner/wrench ?

8mm bi-hex ring spanner will fit it. I use a ratchet ring to save having to keep relocating it.
May need a bigger spanner over the end of it to give enough leverage to crack them.

 

[9designs]

Cheers for that, I’ll order some Torx ring, last time I tried using bi-hex it didn’t go well !!!!

 

[rocky79]

[/quote]

Plenty of info on here but basically all they need to do is loosen the two torx head bolts that hold the motor on. Only just enough to tap the ring round 5-10mm.
Mark the ring and the motor first as a datum point.

I finally got the steering column out. Based on your instructions, how does moving the spacer 5 -10mm helps? the motor position stays the same. Also, should the spacer move clockwise or counter?
Btw, the two bolts holding the motor are 6mm Allen socket head.

 

[enuff_zed]

The spacer slots are not quite concentric and the bolt holes in the column are larger than the bolts, so when you turn the spacer it moves the motor slightly, bringing the worm gear closer or further away from the cog on the column.

 

[rocky79]

The spacer slots are not quite concentric and the bolt holes in the column are larger than the bolts, so when you turn the spacer it moves the motor slightly, bringing the worm gear closer or further away from the cog on the column.

Thank for your reply. I see your point, so is there a way to know the correct position before installing the motor assembly?
Once it’s installed it will be difficult to adjust.

 

[enuff_zed]

The spacer slots are not quite concentric and the bolt holes in the column are larger than the bolts, so when you turn the spacer it moves the motor slightly, bringing the worm gear closer or further away from the cog on the column.

Thank for your reply. I see your point, so is there a way to know the correct position before installing the motor assembly?
Once it’s installed it will be difficult to adjust.

Mark the old one across the motor, spacer and column before you remove it. Mark the replacement motor in the same place and line them all up.
Also consider replacing the bolts with regular hex head ones. Then you can get a ring spanner on them in situ to carry out any further adjustments.

 

[rocky79]

I already marked the spacer and the column. I am still waiting for the motor to come back from ECU Testing.
The bolts are factory 6mm hex head as you can see from the photo. It seems that BMW has already updated them for 2007 as I see many people here saying it’s a 8mm Torx

 

[rocky79]

Also, since the steering column is out, do you suggest replacing the Steering angle sensor? I’ts not cheap $350-400. I just cleaned it, with electrical connector cleaner it was a bit dusty.

I currently have error code: 5E40: DSC: Steering-angle sensor: plausibility.
I was able to do steering calibration before I removed the column and could see the actual steering angle, that means the sensor is working.
I am suspecting since the steering controller was not responding, it’s somehow affecting the steering angle sensor.
I already have 150k+ miles.

Your recommendation is highly appreciated.

Sensor Contacts and PCB trace track were cleaned.

 

[enuff_zed]

I already marked the spacer and the column. I am still waiting for the motor to come back from ECU Testing.
The bolts are factory 6mm hex head. It seems that BMW has already updated them for 2007 as I see many people saying it’s a 8mm Torx

It seems UK had the Torx and US got the allen key type.
I was suggesting you replace them with standard bolts so you can get an ordinary spanner on them in situ.
As long as the spacer and column are marked then you are good to fit the motor back as it came off. All being well it should work like that as ECU Testing sort the ECU, not anything mechanical on the motor.

 

[enuff_zed]

Also, since the steering column is out, do you suggest replacing the Steering angle sensor? I’ts not cheap $350-400. I just cleaned it, with electrical connector cleaner it was a bit dusty.

I currently have error code: 5E40: DSC: Steering-angle sensor: plausibility.
I was able to do steering calibration before I removed the column and could see the actual steering angle, that means the sensor is working.
I am suspecting since the steering controller was not responding, it’s somehow affecting the steering angle sensor.
I already have 150k+ miles.

Your recommendation is highly appreciated.

I am firmly in the school of 'if it ain't broke....'
At that cost, and now you know how easy it is to remove the column, I would leave it alone. It feeds back through the EPS ECU, so until that is fixed you won't know if that was causing the problem.

 

[rocky79]

I am firmly in the school of 'if it ain't broke....'
At that cost, and now you know how easy it is to remove the column, I would leave it alone. It feeds back through the EPS ECU, so until that is fixed you won't know if that was causing the problem.

How easy to remove? lol. I had to pay a mechanic to remove it. He spent half a day taking it out.
I am curious to know if the steering sensor is known to go bad or it’s usually rarely replaced.

I have searched around but did not find anything that is conclusive.