[DaanBMW]

I had some scratches on the passenger side headlight. Body shop attempted to sand them off (then buff and apply UV coating back; or so they said) but now says they are done - can't do much more as it would thin the lens to the point of breaking thru... I don't think they sanded more that 1/8 of a mm (millimeter), if that.

How the heck thin are these OEM lenses? It's not like the scratches were deep to begin with, it's from a pair of ski sliding off the hood to the lens and then down. It could "catch"-your-fingernail deep, but that's it. And it still does.

[rbryantaz]

I haven't done my e90 yet but I just cut off the stock lenses and put on Gsport versions from ebay/china for my e70 X5 which should be very similar....

The stock E70 lens is between 2.5mm and 3mm thick (I just measured 2.9mm on the light path portion of the lens).

[DaanBMW]

One would assume the lens on the e90/e92 is similar thickness.

Is it maybe an issue to sand off say 3/4 of a mm off the lens? Is it becoming too thin and ...might crack? ...or not withstand the high temp of the HID? ...or?

rbryantaz how much work is to replace an entire headlight?

[rbryantaz]

Originally Posted by DaanBMW

One would assume the lens on the e90/e92 is similar thickness.

Is it maybe an issue to sand off say 3/4 of a mm off the lens? Is it becoming too thin and ...might crack? ...or not withstand the high temp of the HID? ...or?

rbryantaz how much work is to replace an entire headlight?

On the e70 it was most of a day to replace the lenses... It was more time consuming than I expected.. If yours aren't that bad just buy a hewdlight sanding kit. That works if they aren't too yellow. I did it on a e46 and it turned out okay. The new lens looks amazing but is more work and I don't know how long it will last. I also tried to put a lamin-x film on it but unless the bubbles dry so far it doesn't look that good....

There are YouTube videos on it. I think the headlight will come out of the e9x much easier where that was a lot of work on the e70 but I would still say it is 2 hours per light easily. You will need a cutter, oscillating tool recommended but a Dremel would work, compressed air, butyl seal rope, a heat gun or oven.

The lenses are available from Gplus or other Chinese suppliers for about $50 a pair. The hard part is cutting off the old lens and getting the channels all cleaned up for a new butyl sealant. The OEM lights are more of a silicone so you can't just heat them and remove the lens, it has to be cut off and then the edges pulled out a couple of inches at a time... Most bake the headlights at 270 degrees to remove and set the new lens but I found that my heatgun worked well and was more controlled....

Vehiculardiy on YouTube did an e90 lens but look at the e70 one too because the e90 was a rework that already had the original sealant removed... I posted about my e70 experience this week so you can read that post.

[DaanBMW]

But for just replacing the headlight with another one (not lens swapping)? If it's 2h including the lens swapping the full removal and re-install should be 1h then?

[Serf27]

Replacing the whole light is faster than replacing the lens, but the cost is much more.

There are headlight lens that are beyond repair where they have cracks deep in the plastic.
Maybe that’s your case since they couldn’t be sanded out?

[tcphoto]

I remember how easy it was to swap new lenses on my old E46, those days are gone. Now, you need to perform surgery in order to do it cheaply. Here is a video on how to do it well, I'll do so when I run out of lens material to sand.

[DaanBMW]

Yeah, that's what's going on now. Shop will try to sand again to get the whole thing out. If it goes sideways (if thk is 2.5 min if shouldn't...) I'll look for a used headlight.

Which begs the question - does a headlight swap need any kind of programming/registration? Have INPA but nothing more.

[DaanBMW]

anyone know if any registration is needed when replacing an entire headlight assembly?

[Serf27]

I looked at the lens today, it’s pretty thin, but you’d have to sand off a lot of material to sand through the plastic. Unless like I said above, the cracks are deep in the plastic.

If you get another headlight, you can swap over your modules, to avoid any programming.
Most of the time, I can swap a headlight with no issues and it doesn’t need programming. There’s only been 2x where it was needed for the adaptive module.