MOT failure

dan_b

dan_b

A2OC Donor
Well, that's never happened before.

My car's just failed its MOT on the headlights. "Dazzling oncoming traffic, problem with light unit, not the aim itself" apparently.

I've got Xenons in a normal reflector lens, is it possible the Xenons may caused the MOT failure? Should I just whack the bulbs out and put the stock H7s back in do you think? Is anyone around near Richmond who could help me align them properly this weekend?

Dan
 
If your headlamp lenses (more like clear cover!) are undamaged and un-crazed, and the reflectors are also in good nick, it must be the xenons Dan.

How is the cut-off on the dipped beams (nice and sharp)? If it is sharp then an easy way to adjust the alignment is to find a totally flat piece of land with a wall that you can drive right up to.

Get the bumper just about touching the wall and mark the cut-off with chalk. Then reverse 20 feet and note where the cut-off is now. It should have dropped about 8cm if all is well.

This wasn't an Audi dealership by any chance? They are sometimes real sticklers for aftermarket xenon kits.

If the cut-off isn't sharp, then the best bet is to stick normal H7s in and go back, then revert to xenons for everyday use, but watch out for Mr Plod.

Cheers

Mike
 
You can get a specially designed lamp which I have just bought, I'll fit this weekend and post the pics for the 2 types, they are supposed th deal with the glare problem that aftermarket xenons cause in free form reflectors.
PS anybody actually know of anyone 'done' by BiB for this?
Mike
 
Our A2 has the same kit as Dan's and it got through the NCT (our version of the MOT) earlier this week. It's more stringent than the MOT so I'm surprised that you had a problem. It's worth trying a headlight alignment first before you start swaping the bulbs out.

We did replace a headlight about a year ago as the glass was "frosted". Seemingly it's a known problem.
 
Well having had a chance to look at the MOT report, all it actually says is that the offside headlamp aim is poor causing dazzle and needs aligning. The garage said they couldn't do it and I would have to take it to Audi to get the headlight fixed. I tried speaking to the mechanic who did the MOT but he didn't know what I was talking about. Maybe it is just the aim afterall - perhaps it's pointing too far to the right?

It wasn't an Audi dealer, but it was a large franchise garage - they were offering 1/2 price MOTs. Doh.

Any tips on how to get my offisde light aim right both in terms of vertical and horizontal aim?
 
Simple Dan - pop the bonnet and there are 2 white plastic adjustment screws at the back of the headlamp. The inner one adjusts vertical alignment and the outer one controls horizontal.

There's absolutely no reason why they couldn;t adjust it for you (after issuing a failure, they would do the adjustment and then pass it - that's what my local one does).

Cheers,


Mike
 
Thanks Mike. I think they are just stupid mechanics - I wasn't able to explain over the phone as they weren't able to explain what the fault was they just said they coulnd't fix it and it needed to go back to Audi. They probably have that half-formed memory that you can't pop the bonnet on the A2?

What's the correct angle of attack for the offside headlamp?
 
dan_b said:
They probably have that half-formed memory that you can't pop the bonnet on the A2?
Click to expand...

I use a 'while you wait' MOT test centre and they always remove the bonnet for a general inspection and check for leaks and condition of the brake reservoir and pipes etc. I though this was a mandatory part of the test

Cheers Spike
 
I normally do, but I thought I'd give this bigger garage a go with it's "cut price" deal- now I know why, cut price quality!
 
The simple way to do the alignment is as follows:

Assuming that one headlamp is fine, park up by a flat wall and put the dipped headlamps on.

Then, you can assume that the lower beam is the correct one and you just have to adjust the other one to match in level.

Please double check the the HID bulb is seated correctly, as this is a major cause of mis-alignment and I suspect that it's the case here too.

You'll need a large allen key to turn the adjusters (8mm from memory, but double check) and it's the inner one that controls height.

Cheers,

Mike
 
Yeah, I'll check the HID seating first, I know they're quite difficult to get right with all the cabling behind them etc.

IN terms of left-right alignment of the offside lamp, is there a rough measure of where it should be?
 
It should pretty much point straight ahead, as should both beams. If you drive up to the wall, mark the beam positions and then reverse, apart from dropping, the beams shouldn't splay out or move in, but remain the same distance apart from each other, which is the same as the distance between the headlamps, as mounted.

Cheers,

Mike
 
You're not wrong! However, the technology of HID has improved so much in the last couple of years that I now feel there is a case for allowing retrofits on safety grounds.

As long as a light is dipped correctly, sharply defined and of the right colour, I see no reason why drivers shouldn't benefit from improved lighting at night.

Cheers,

Mike
 
Ok so I thought I'd attempt to correctly align my offside (drivers side) headlamp at the weekend as I don't believe it's the HID that they failed me for.

First checked the seating of the HID bulb - that seems fine (although you can see it is possible to clip it in incorrectly if you're ham-fisted with it).

Second, checked the vertical alignment - this was a bit lower than the nearside, so brought that up level with about 1 turn of the screw.

Lastly, checked the horizontal (left-right) alignment - this is the one I assume was the issue. I cranked it fully leftwards until the adjustment screw would turn no further, but to be honest I couldn't actually see the bulb pattern moving? It should have done surely?

Is there someone around who could help me double check the alignment is correct or whether the headlight unit is in fact faulty? Got another week until the MOT re-test.
 
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