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Headlights again

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ori
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Headlights again

Post by ori » Mon Apr 10, 2017 6:59 pm

Well, my headlights have been pointing to the ground again. So let me fill you in and I need some advice please. Yes I have read other threads and hence my post.
2016 Z4 35is

So One day I was driving along and my headlights were pointing to the floor. Taken to BMW and they just manually adjusted them up. I said this can't be right and they said its all fine. Anyway, week later I am back and this my my headlights are pointing to the sky. This time the find a "chaffed wire".
I invested in a code reader and discovered a front level sensor. So the car went in and that got replaced.
A few weeks later, and again my headlights are pointing to the floor. I videoed it and sent it to my BMW dealer who says it looks normal??? The beam has a clear cut off point about 1.5 car lengths in front of me. It doesn't even light up a number plate of a car in front of me. I remember these lights being bright and lighting up the road ahead of me for some distance. Am I wrong?

Basically, I think there is something still wrong with these headlights. The car is going back in tomorrow to get looked at again, but What I would really like to do is to compare to another Z4. Anyone in NW London per chance?

Thoughts?

ori
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Headlights again

Post by ori » Mon Apr 10, 2017 11:10 pm

Well, just to update.

I have just gone for a drive and the lights were way up high and giving me beautiful lighting. I have two videos. The only difference is that one had the roof down and one had the roof up.
I think I noticed that the lights change height massively when going over a bump. I am not sure though.

dk345
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Headlights again

Post by dk345 » Fri Apr 14, 2017 12:52 am

I'm pretty sure you're experiencing a problem that I and many other people on this forum have done. In fact I only had to deal with this 2 or 3 weeks ago. A quick search will probably bring back a few threads within the last six months where others have had issues with the aim of their headlights.

Quite a few people have "fixed" the issue by opening up the bonnet and manually adjusting the aim of the beams. Like you, I'm of the opinion that this just can't be right. On my car the lights can be angled perfectly one day and straight down to the floor the next, then magically fix themselves again the day after.

Having done some reading around on the internet, I think the problem is caused by the auto-levelling sensors for the xenon headlights. Apparently there's one in the front driver wheel arch and one in the rear driver wheel arch. They're used to tell the lights when to pitch up or down when the car goes up or down hills, so you don't dazzle other drivers.

Image

If you drive over a large pothole, or a particularly bumpy road, these sensors tend to get a bit confused and get stuck in the "going up a hill" position. Having had quite an in depth look around the internet it seems to be a problem that affects all models of the E89's generation, so the E9x 3 series, some X models, etc.

Here's a link on another Z4 form that I managed to find that explains the problem quite well (complete with diagrams!): http://e89.zpost.com/forums/showthread.php?t=418453

As the sensor is just getting "stuck" in the wrong position it's not outputting error messages to the car's control systems. So if you take it into the dealer or plug a code reader in you're not going to find anything untoward, it's not actually "faulty", so it won't get replaced. I suspect this is the problem you're having, and this can be proved by disconnecting the sensors (I believe there's a how-to in that link above). With the sensor removed the headlights will always stay in the standard aim angle, and not bother moving around for hills or bumps at all. So, if your lights are currently aimed too low and you unplug these sensors and try again then they should be at the correct height.

I never actually did this as it meant removing wheels and arch liners that I just can't do in my flat's car park. So my way of fixing it is to go and drive the car. You need to find a way of sharply increasing the angle of your car... So, for example, flooring it from 0 to something stupid. The acceleration forces the car to change angle, and can sometimes (once, in my experience) force the lights to reset. Another one (and my preferred solution) is to go and find some speed bumps. There's a cracking combination at my local Tesco of two harsh bumps close together. Every time my lights have been angled too low I've gone over these bumps at about 10mph and they've shot straight back up to where they belong. In fact, here's a link to the exact place: https://goo.gl/maps/uENyuv5L3ym The larger zebra crossing bump unsettles the lights (you can see them bounce around when it's dark) and then the smaller bump snaps them back in to place. In the year I've owned the car I've tried to fix the lights using those speed bumps three times, and it's worked three times.

My lights seem to go wrong quite a lot. Maybe it's because the quality of my commuting roads is absolutely shocking. I've taken the car into BMW when the lights have been wrong and all they've suggested is to re-aim them using the screws under the bonnet, and I really don't think that's the solution. If my headlights gradually got worse over years and years then fair enough. But these "break" and "fix" themselves all on their own, or just by me driving the car... So how can it be a problem with the manual aim? That's why I think the culprit is these sensors.

I notice in your post that there may be a link between roof up/roof down and broken lights... That's not something I've experienced. In fact, you've even said "I think I noticed that the lights change height massively when going over a bump. I am not sure though." which backs up my theory of confused sensors and needing a sharp change of angle to sort them out again. It is possible that there is a fault with your car, or with these sensors, but if you've got the time and space to take wheels off an unplug sensors then it should tell you pretty conclusively if that's an issue.

Sorry for the long and rambling post... Been a long day here. Hope it all makes sense!
Last edited by dk345 on Fri Apr 14, 2017 4:47 pm, edited 1 time in total.
2013 Mineral White 35iS

flybobbie
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Headlights again

Post by flybobbie » Fri Apr 14, 2017 6:50 am

Did someone have a problem with the rear sensor arm reversing.
I think it took some repositioning to fix. Try the US forum http://e89.zpost.com/forums/showthread. ... headlights
By the way that diagram shows them on the wrong side of the vehicle.
I would jack up the vehicle and have a look to see if the arms are pointing forward.
Last edited by flybobbie on Fri Apr 14, 2017 8:31 pm, edited 1 time in total.

dk345
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Headlights again

Post by dk345 » Fri Apr 14, 2017 4:46 pm

flybobbie wrote: Fri Apr 14, 2017 6:50 am By the way that diagram shows them on the wrong side of the vehicle.
In think you're right. The diagram was originally taken from real OEM, where I assume the images will be tailored toward the German market, so driving on the other side. The actual part location is "offside", so yes, driver's side rather than passenger's.
2013 Mineral White 35iS

flybobbie
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Posts: 4015
Joined: Sat May 25, 2013 8:27 pm
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Headlights again

Post by flybobbie » Fri Apr 14, 2017 8:24 pm

dk345 wrote: Fri Apr 14, 2017 4:46 pm
flybobbie wrote: Fri Apr 14, 2017 6:50 am By the way that diagram shows them on the wrong side of the vehicle.
In think you're right. The diagram was originally taken from real OEM, where I assume the images will be tailored toward the German market, so driving on the other side. The actual part location is "offside", so yes, driver's side rather than passenger's.
I think the US version on the right so diagram totally wrong.

http://e89.zpost.com/forums/showthread. ... headlights

ori
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Posts: 1497
Joined: Sun Mar 18, 2012 4:04 pm

Headlights again

Post by ori » Mon Apr 17, 2017 9:30 pm

dk345 wrote: Fri Apr 14, 2017 12:52 am I'm pretty sure you're experiencing a problem that I and many other people on this forum have done. In fact I only had to deal with this 2 or 3 weeks ago. A quick search will probably bring back a few threads within the last six months where others have had issues with the aim of their headlights.

Quite a few people have "fixed" the issue by opening up the bonnet and manually adjusting the aim of the beams. Like you, I'm of the opinion that this just can't be right. On my car the lights can be angled perfectly one day and straight down to the floor the next, then magically fix themselves again the day after.

Having done some reading around on the internet, I think the problem is caused by the auto-levelling sensors for the xenon headlights. Apparently there's one in the front driver wheel arch and one in the rear driver wheel arch. They're used to tell the lights when to pitch up or down when the car goes up or down hills, so you don't dazzle other drivers.

Image

If you drive over a large pothole, or a particularly bumpy road, these sensors tend to get a bit confused and get stuck in the "going up a hill" position. Having had quite an in depth look around the internet it seems to be a problem that affects all models of the E89's generation, so the E9x 3 series, some X models, etc.

Here's a link on another Z4 form that I managed to find that explains the problem quite well (complete with diagrams!): http://e89.zpost.com/forums/showthread.php?t=418453

As the sensor is just getting "stuck" in the wrong position it's not outputting error messages to the car's control systems. So if you take it into the dealer or plug a code reader in you're not going to find anything untoward, it's not actually "faulty", so it won't get replaced. I suspect this is the problem you're having, and this can be proved by disconnecting the sensors (I believe there's a how-to in that link above). With the sensor removed the headlights will always stay in the standard aim angle, and not bother moving around for hills or bumps at all. So, if your lights are currently aimed too low and you unplug these sensors and try again then they should be at the correct height.

I never actually did this as it meant removing wheels and arch liners that I just can't do in my flat's car park. So my way of fixing it is to go and drive the car. You need to find a way of sharply increasing the angle of your car... So, for example, flooring it from 0 to something stupid. The acceleration forces the car to change angle, and can sometimes (once, in my experience) force the lights to reset. Another one (and my preferred solution) is to go and find some speed bumps. There's a cracking combination at my local Tesco of two harsh bumps close together. Every time my lights have been angled too low I've gone over these bumps at about 10mph and they've shot straight back up to where they belong. In fact, here's a link to the exact place: https://goo.gl/maps/uENyuv5L3ym The larger zebra crossing bump unsettles the lights (you can see them bounce around when it's dark) and then the smaller bump snaps them back in to place. In the year I've owned the car I've tried to fix the lights using those speed bumps three times, and it's worked three times.

My lights seem to go wrong quite a lot. Maybe it's because the quality of my commuting roads is absolutely shocking. I've taken the car into BMW when the lights have been wrong and all they've suggested is to re-aim them using the screws under the bonnet, and I really don't think that's the solution. If my headlights gradually got worse over years and years then fair enough. But these "break" and "fix" themselves all on their own, or just by me driving the car... So how can it be a problem with the manual aim? That's why I think the culprit is these sensors.

I notice in your post that there may be a link between roof up/roof down and broken lights... That's not something I've experienced. In fact, you've even said "I think I noticed that the lights change height massively when going over a bump. I am not sure though." which backs up my theory of confused sensors and needing a sharp change of angle to sort them out again. It is possible that there is a fault with your car, or with these sensors, but if you've got the time and space to take wheels off an unplug sensors then it should tell you pretty conclusively if that's an issue.

Sorry for the long and rambling post... Been a long day here. Hope it all makes sense!
Thank you for the most detailed response. I think you are spot on, but this can't be a solution as at the end of the day I can't always find a speed bump driving down a motorway at night.

Just to update on situation. The car did report an error on the front level sensor which was replaced and the problem persisted. It has now had the rear sensor changed as well and I will keep an eye on the lights. I find it frustrating that a a new car suffers these issues. I also found it frustrating that I was told the lights are performing normally. Only when I should videos to a tech on 2 nights on the same road did he understand that there was a problem.

The other issue is that my keyless entry system has failed on one side of the car. Part was on a back order. Took 3 weeks and when it arrived it was the wrong colour. Now have to wait another 3 weeks for the part. Not great from BMW.

TBF to the dealer, they are taking this matter seriously and are doing their best.

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