Swapping Pre for post facelift bumper + foglight mod writeup

Greeno

Active member
St ives, Cambs.
So the story: my old, prefacelift bumper had a nasty scuff thanks to the previous owner on probably high curb. Then some oik put a scuff down the side of it. Oh and also one of the fog light lenses was cracked.

So getting a re-spray, repair and fog replacement was going to cost a few quid…

Then JDM decided to sell his facelift bumper which I snapped up. The game was on….

The bumper arrived and was in pretty good condition, not far from perfect and a colour match so no respray needed.

Next the fogs. i ended up getting 5 second hand fogs. I got 1 where there was no corrosion and the light was mint but the black mounting frame was broken. I then got another 2. they had corrosion and the frames were broken. You can not buy the mounting frames from BMW – they are part of the light unit. Finally I got hold of a pair that had corrosion but the frames were good, all for a couple of quid.

As I couldn’t use the lights due to the corrosion I pondered what to do…..

So I decided to split open the lens and install an array of 5 LEDs in each.

Facelift fog lights fail due to corrosion. The corrosion causes the seal to separate from the body. So a lot of huffing and puffing later and I managed to totally split the lights. I would say that to cleanly split lights without corrosion would be impossible unless you do a cut and shunt. So the split and cleaned up lights:


IMG_1569.jpg


I then sprayed the metal portion black (this isn’t the final finish, I went for a matte final finish)

IMG_1570.jpg


Although the LED’s don’t look evenly spaced – they are, it is just down to the angle. It was a right pain in the arse getting the LED’s all pointing in the right direction, parallel and perpendicular to the flat plane as there are so many angles in the lights. I went through a load of araldite getting them right.

With the lens on:

IMG_1573.jpg


Final check before install;

IMG_1574.jpg


Installed off:
IMG_1602.jpg


installed on:
IMG_1603.jpg


I have std HID’s and the fogs look quite white in comparison so I think I need a change of bulbs.

Not that I ever really use the fogs, but I quite like the fact it is dark there rather than the shininess you get as standard from the silvering.

I need to sort out my head lamps now as the plastic is a bit milky. Also I sprayed the kidney grills black and they are showing signs of age now after 3 years or so. So they need redoing.

I used the bumper removal guide. Big thumbs up to that.

Now, a pre facelift bumper is NOT a direct replacement for a post facelift.

On pre facelift cars at the sides, behind where the reflectors are on the post facelift there is a little nubbin:

IMAG0220.jpg


The one just to the left of the crease in the wing. You have to chop this off. Like this:

IMAG0221.jpg


This is due to the extra thickness of the bumper at that point due to the reflector.

Also the bolts on the underside do not line up. But there is nothing you can do about that.

Greeno
 
Is the undertray the same shape at least? Even if the bolts don't line up perhaps you can drill some new holes in your undertray to line up with the post-bumper?
 
nice write up Greeno.

I'm wondering how to best tackle a similar job. One of the brackets on my fogs has broken and I've now go a spare set so i'm going to do a swap round and hopefully select the best reflectors to make a good pair. I was wondering if it would work to cut a plastic panel that you could stick into the back of the reflector to make it level and then fix individual LEDs through that, hide the wiring behind the infill panel maybe. the new LEDs could sit tight behind the lens in theory and if sealed well there would be no danger of moisture getting in the front of the lens...I'm tempted to have a go at this as I've 2 sets of lights, 1 with a broken bracket, but 2 sets of lenses...
 
Hey Greeno,

Great write up thanks. I’m also suffering with one misty front fog light. Just like yourself I’d like to fix myself rather than pay for new replacement fog lights. I’ve already had them out - lens like new, black plastic surround fine, but chrome section is in an awful state. I’m stuck with my refurb because I simply cannot separate the clear lens from the chrome section. Tried running a new Stanley knife blade - didn’t work. Also tried heat, pulling and prising ‘gently’ with a plastic trim tool. I know water is getting in as I can see where the bonding substance is rubbish but I think too much of it is still ‘bonding’ to prevent me from getting the two sections separated.

Any help would be gratefully received!
 
I'm interested in doing this due to the constant condensation. Wouldn't it be easier to use LED waterproof strip lights as a drl or wouldn't they be bright enough?
 
Sorry to revive a dead thread but I think it's going to be worth it...

Having wanted a Z4 for years now, I finally got my hands on one early February. One of the things that I've had issues with is one of the fogs not working. A Google search brought this thread to my attention.

Greeno could you possibly help me with where you got the leds from please? The reason being the Z4 I picked up in February was the one you had!!!20250130_065813.jpg
 
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