Weird D2 sunroof issue
 

My 2002 A8 sunroof opens only slightly, then immediately reverses the action but fails to close correctly. I have replaced the switch, but the fault remains.
I can mechanically fully open and close the sunroof using an Allen key.
Are there limits switches involved?
Any suggestions please?
Many thanks.
DailyMike.

The sunroof has a pressure relief system like the windows do, for injury mitigation.

I would suggest lubricating the mechanism using teflon or silicone spray (so as not to damage the plastics, or leave a sticky surface).

Mine had similar issues this summer and was quite dusty. I cleaned as best I could with a rag and a toothbrush and lubricated, which fixed the issue.

Thanks for your prompt advice, Marty...I'll give it a go later today.

When you said "the mechanism", do you mean everything in sight when the sunroof has been wound fully open using an allen key? Did you remove the motor at any stage of the cleaning procedure?

Cheers,
Mike.

Never touched the motor, just cleaned and lubricated all the bearing surfaces I could find. With the sunroof open (I managed to get it open at some point without using the crank handle - you find that attached to the fuse box cover I believe, though I expect the Allen key approach is fine).

I even put some chain "chukka" grease that I had to hand on the sliding mechanism and also on the small depression at the front that the sunroof looks like it hinges on when lifting the rear. Not sure that's done anything, as the depression (semispherical?) has failed to reveal any marks of usage. It might just be a clearance moulding.
I'm going to keep an eye on this grease for dirt collection, as the mechanism is difficult to access. The sunroof did have a grease of sorts already in there - synthetic lithium or something from what I recall reading from somewhere.