# How to adjust the glass sunroof panel to achieve a flush fit with the roof



## IrishPhaeton (Jul 21, 2006)

*Sunroof wind noise*

I collected a 6 month old demonstrator Phaeton on Friday to replace my previous 3 year old.
It's interesting all the little changes in the upgrade model, and it has (to me) a different feel. Quite a bit of this may be due to the 19" wheels which do contribute quite a but more road noise at higher (motorway) speeds.
My real query is the sunroof on this car. I hear significant wind noise from the closed roof at higher speeds (an indicated 80 to 90 mph). On inspection I suspect that the front lip of the sunroof is a few mm proud of the roof. 
Has anyone any comment on this, and can it allinged.
Thanks


_Modified by IrishPhaeton at 9:43 AM 5-25-2008_


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## PanEuropean (Nov 3, 2001)

*Re: Sunroof wind noise (IrishPhaeton)*

Hello Hugh:
The cause of the wind noise is as you speculated - the fact that the leading edge of the sunroof is standing proud from the roof.
Adjusting the sunroof for a flush fit is very easy to do - probably one of the easiest tasks on the list for the owner to adjust.
I have to make a small adjustment to my sunroof this afternoon for exactly the same reason - I'll take some photos and post them later today. In the meantime, go rummaging through your collection to find your Torx screwdrivers - you will need one of them to do the job.
Michael


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## PanEuropean (Nov 3, 2001)

*Re: Sunroof wind noise (PanEuropean)*

Hi Again Hugh:
Here's how to fix the problem.
Place the sunroof in the 'vent' position (in other words, with the trailing edge of the sunroof up as far as it will go). Then turn the vehicle ignition off.
Reach up and *very gently* tug the upper aft edge of the pleated rubber skirt back about 1/8 to 1/4 of an inch. This should be sufficient to allow a little rubber mushroom on the pleated panel to drop clear of the retaining opening that it is fitted to.
*Release the mushroom at the back of the rubber pleated skirt*








I apologize that the contrast is not too good in the photo below.








Now, gently pull the entire upper edge of the pleated rubber skirt away from the lower edge of the glass sunroof panel. You do this by starting at the aft edge, where the mushroom is, and just tugging the upper edge of the skirt inwards toward the center of the car. It is a friction-fit, and very little effort is needed to remove it.








Once you have the upper edge of the skirt free from the lower edge of the sunroof panel, you will see that there are three Torx fasteners visible. These are the fasteners that allow up and down movement of the sunroof.
You now repeat the same process for the other side of the car.








Once you have both of those rubber pleated skirts disconnected from the glass sunroof panel, turn the ignition on, and close the sunroof. You will need to hold the rubber skirts inward (bent downward 90 degrees, toward the middle of the car) as you do this, to ensure that you have easy access to the three screws.
I have found that it is easiest to adjust the front end of the sunroof first, then adjust the rear (trailing edge) end second. This is a heck of a lot easier than trying to adjust both ends at the same time.
So, loosen the front and middle screw on both sides of the car. Don't loosen the aft screw. Now, gently push the glass panel up or down (as required) until you have the correct gap specification. Obviously, the glass panel is not flexible, so it is useful if you have a helper on the other side of the car who can mirror your actions.
Once you have the panel in the correct position, have the helper hold it in place. This is accomplished by having the helper, who is standing just outside the open front door, hold both the top and bottom portion of the glass while you are sitting in the front seat.
Now, gently tighten the *front screw only.* Repeat the process for the other side of the car. The torque specification for the screw is 4.5 N·m, which is actually less than finger tight. Whatever you do, don't reef the screw in really tight - if you strip it, you are going to be in a world of hurt. Just tighten it very gently.
Now, loosen the aft screw on each side (the middle screw is still loose, remember?) and repeat the adjustment process for the rear. This time, tighten both the aft and the middle screws once you have the glass panel in the desired position.
Finally, turn the ignition on, adjust the knob so that the aft end of the glass panel is fully up again, and re-install the rubber pleated skirt. If you look closely, you will see that there are four little 'clips' that match up with similar openings on the glass panel frame. Again, it's just a friction fit. Tug the skirt back at the top rear, put the mushroom back into the glass panel frame, and voila, you are done.
The adjustment specifications call for the glass panel to be between flush and 1 mm lower than the metal roof at the front, and between flush and 1 mm higher than the metal roof at the back. As you can see from the photo of my car below, the curvature of the glass panel does not precisely match the curvature of the roof. So, I averaged things out - the panel is flush at the front outboard edges, and 1 mm below the steel roof in the middle, which complies with the specification. At the rear, it is flush at both the outboard ends and the longitudinal centerline of the vehicle.
*Adjustment Specifications*








Finally, you might as well perform an adaptation of the sunroof motor mechanisms before you call it a day. This will ensure that the sunroof operates properly, and also ensure that when you have the glass panel open (slid aft), the air deflector will move up and down automatically as the vehicle speed increases and decreases. To adapt the sunroof, see the instructions that are on this thread: 
How to adapt moving components (windows, seats, sunroof, trunk lid)
The process for adapting the sunroof is not particularly complex, but the instructions are very poorly written. Heck, they are poorly written in the original German! So, print the instructions out, read them about half a dozen times until you are certain you comprehend what the series of actions are, then, carry out the appropriate actions.
Michael


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## ciscokidinsf (Feb 17, 2008)

The mom walking with the child back there is clearly saying to the kid: 'Don't look at the crazy man with the car, honey'


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## IrishPhaeton (Jul 21, 2006)

*Re: Sunroof wind noise (PanEuropean)*

PanEuropean
Great News! Really appreciate your help in this. I look forward to the silence..
Hugh


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## mattsimis (Sep 19, 2005)

*Re: Sunroof wind noise (IrishPhaeton)*


_Quote, originally posted by *IrishPhaeton* »_I collected a 6 month old demonstrator Phaeton on Friday to replace my previous 3 year old.
It's interesting all the little changes in the upgrade model, and it has (to me) a different feel. 
_Modified by IrishPhaeton at 9:43 AM 5-25-2008_


What colour is your new model? I seen a silver one zoom past me the other day, the first one Ive seen in Ireland.


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## IrishPhaeton (Jul 21, 2006)

*Re: Sunroof wind noise (mattsimis)*

Its Reflex Silver, Navy Blue Sensitive leather, 19"Helois Alloys + lots of other toys ( Keyless entry, voice activated phone, cornering bi-xenon etc)
A visit to VRT today indicate a new policy since the last one I imported, I expect a very nasty bill to follow for "extras"....









I was laid low over the weekend, so have not used the car since collection on Friday, it's still on Belfast TEZ plates.


_Modified by IrishPhaeton at 1:29 PM 5-26-2008_


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## WillemBal (Nov 20, 2010)

PanEuropean said:


> Place the sunroof in the 'vent' position (in other words, with the trailing edge of the sunroof up as far as it will go). Then turn the vehicle ignition off.
> Reach up and *very gently* tug the upper aft edge of the pleated rubber skirt back about 1/8 to 1/4 of an inch.


Hi Michael,
I am experiencing some whistling noise from my sunroof ever since I got the car and now I'm trying to fix the problem. My roof is actually a solar roof and I'm wondering whether the same construction and procedure applies. When the roof is closed, I can see a cover with the same upholstery as the remaining part of the inner roof, with a vent grid in the middle. Also, the same control know is present with the same functions.
I can grab the roof cover by hand when I open the roof 1/3 and then slide it aft, revealing the back side of the solar panel. The whole construction which is then visible is about identical to the third photo (except that it is all black and has a small transducer module fitted in the centre). 
But the big difference is that there are no rubber skirts as per your first two pictures.
The question is whether these rubber skirts are there for aesthetic reasons (with the solar roof, you normally never see the back side of the solar panel), or whether they serve a particular purpose with respect to reducing wind noise.
I measured the flush fit of the roof at the front. At the left side, it is flush within 0 mm, and at the right side it is +1 mm with respect to the flush situation. The question is, whether such a small deviation from the specified can account for whistling noises, already noticeable at speeds near 50 km/h. In addition, I noticed a very strange phenomenon: When I accelerate heavily from 30 to 100 km/h, this whistling becomes very loud and with a strange modulation in it. The amount of whistling then gradually reduces to "acceptable levels" when the speed then is kept constant. In the beginning, I thought that I was hearing the sound of the fuel flowing through the tubes, as during such acceleration moments, the fuel consumption increased up to 99 litres per 100 km. It puzzles me!
Willem


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## PanEuropean (Nov 3, 2001)

WillemBal said:


> But the big difference is that there are no rubber skirts as per your first two pictures. The question is whether these rubber skirts are there for aesthetic reasons (with the solar roof, you normally never see the back side of the solar panel), or whether they serve a particular purpose with respect to reducing wind noise.


My understanding is that the rubber skirts are there to reduce wind noise, and I believe that they would also have been fitted to cars equipped with a solar panel sunroof. But, I would not bet the rent money on this, because we didn't get solar panel sunroofs in North America, and I don't have any photos of ROW vehicles with an open solar panel sunroof to check this against.



WillemBal said:


> I measured the flush fit of the roof at the front. At the left side, it is flush within 0 mm, and at the right side it is +1 mm with respect to the flush situation. The question is, whether such a small deviation from the specified can account for whistling noises...


I think that is unlikely, if you are within 1 mm, that is about as close as you can get.



WillemBal said:


> When I accelerate heavily from 30 to 100 km/h, this whistling becomes very loud and with a strange modulation in it. The amount of whistling then gradually reduces to "acceptable levels" when the speed then is kept constant.


The air deflector at the front of the sunroof aperture adjusts position in response to the vehicle speed. VW determined that at different speeds, different air deflector positions were needed. If you increase or decrease the vehicle speed rapidly, it will take a moment for the air deflector to "catch up" and reposition. 

Next time you are driving with the sunroof open, put your hand out the hole and rest the palm of your hand gently on the air deflector. Then, accelerate from about 30 km/h to 120 km/h. You will feel the air deflector repositioning as the vehicle speed changes.

You might want to check and see if there is any debris under the air deflector that might be interfering with its ability to move.

Michael


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## aaron843 (Oct 16, 2010)

*One side higher than other*

I am getting a whistling noise from my sunroof with it closed at about 60-70mph. It looks like the right side is about 1mm higher than the driver's side.

This noise was preceded by another noise, scraping when opening. This makes me think some debris may be trapped.

Upon initial inspection a minimal amount of dirt can be found. I've looked with a flashlight with the roof in each open position. Are there any less than obvious places to look for debris in the sunroof?


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## WillemBal (Nov 20, 2010)

Hello Michael, 
Thanks a lot for your elaborate reply. This weekend was the first two-day period on which I had no other obligations (my wife would not agree with this) so I did some thorough investigations on the sunroof problem and some other issues I was having. 

First, I must say that you were responding to my questions by addressing another issue, i.e. the operation of the deflector. Actually, I was referring to the wind noise which becomes audible with the sunroof *closed*. To cope with this, I first thoroughly cleaned all rubbers of the sunroof and the corresponding rectangular opening in the roof. I also cleaned everything else I could see with the sunroof opened, i.e. cleared all debris (very little) as well. 
Then I closed the sunroof to perform the next step of what I believed would help to fix the issue. I grabbed my expensive bottle of seal lubricant (Gleitmittel G052172A1, recommended for rubber seals) and applied a trace of it in the seam between sunroof and the opening in which it fits, of course with the sunroof closed. I only used a little, but just enough to see that the fluid had completely filled up the seam and would stay there as long as the sunroof would kept closed. Next morning, the fluid had been diffusing itself all over the rubber surfaces, so that already looked much better. I must say, that the noise during my first test drive was noticeably less than before. My guess is that the rubber now is more flexible than before and also may have swollen a little bit, just enough to ensure a better fit than before. So this is the original sunroof problem, not related to the deflector, I think. 

As far as the deflector is concerned, I followed your recommendation and tried to probe the position of it by holding my hand lightly over the deflector while the sunroof is opened. I noticed that it DOES respond to the vehicle speed, but only in a "binary" manner. I.e. while parked, it is fully upwards. About an inch or so of the front vertical side protrudes above the roof. While speeding up, it stays there until 80 km/h is exceeded. Then the deflector retracts, with the front side of the curved part about 5 to 10 mm *below* the surface of the roof. It cannot remember any other positions than these two, so I wonder whether there is a fault, since the deflector does not respond to the vehicle speed in an analogue manner. 
I also tried to pull the deflector down at lower speeds to hear whether it would reduce noise in any way. That was the case; when the front end of the deflector is kept flush with the roof, the wind noise was much less than when I released it and let the car determine the right position. I wonder whether there is any fault, or perhaps it is something which was improved by later roof controllers, either by hard- or by firmware? I'm also puzzled why it stays protruded for such a long time, which does not seem ideal for optimal deflection at any speed, and then suddenly retracts the deflector 10 mm below a position which seems to be the "logical" optimum. 

Talking about the deflector; today I encountered an interesting phenomenon about the deflector. I needed to fix a couple of other things, so I had removed the C-pillar trims, the rear seat cushion and backrest, and both parts of the hatshelf (the one with the sunshade and the one in the trunk with the electronics module. Because I needed to test some of the backrest motors and the sunshade motor, I decided to pick up the regulated laboratory power supply from my office. During my trip (of course the airbag warning light came on), I opened the sunroof. To my surprise, the infamous "whopping" started, between 35 and 60 km/h. It was very loud, very much as if all windows were open. The sound of my radio was very distorted too, as if it was chopped at a frequency around 10 Hz. Again I tried to manually "adjust" the height of the deflector, but this time, the whopping sustained. Whatever I did, increasing the speed above 35 would start this whopping sound and only disappeared by partly closing the sunroof or decreasing speed below 35. Very strange... 
The only explanation that I can think of, is that the total resonance volume inside the cabin was increased with the volume of the trunk, and that the deflector is not capable of eliminating resonances at very low frequencies. Of course it is not a serious problem, as I was driving with a partly stripped car. But too interesting not to mention. 

Meanwhile, I hope that someone or can comment on the operation of the deflector, whether it has just a limited amount of different positions, i.e. fully retracted, fully out and something in between, or whether it positions itself on a continuous basis? 

Willem


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## Zaphh (Jul 5, 2008)

Mine works on a continuous way. 

P.


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## PanEuropean (Nov 3, 2001)

WillemBal said:


> ...comment on the operation of the deflector, whether it has just a limited amount of different positions, i.e. fully retracted, fully out and something in between, or whether it positions itself on a continuous basis?


 Hi Willem: 

I believe that the deflector on my car (a 2004) has several different positions - I don't think it moves on a continuous basis. 

Michael


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## Zaphh (Jul 5, 2008)

To be more precise, I don't know whether it has several positions or whether its position is a continuous function depending on speed, but it does not move in a discrete way. 

Whatever it is, it is not binary. 

P.


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## WillemBal (Nov 20, 2010)

Thanks, Michael and Pierre,
I will observe its operation during the next couple days. Spring is in the air this week!

Willem


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## WillemBal (Nov 20, 2010)

Hi all,
I couldn't bear the whistling noise any longer. Already 4 times I readjusted the roof with various heights without avail. My youngest son couldn't resist teasing me on various occasions by imitating this annoying whistle. It was time for more drastic measures.
Last weekend, I decided to remove the glass (solar) panel, which was surprisingly simple by removing the 6 screws, described above by Michael. With the panel on the table, I could easily remove the rubber seal, which was completely wet. Lots of water had accumulated between the rubber seal and the groove in which it was secured. :what:
Upon further inspection, the (hollow) seal appeared to be full of water inside as well. From the presence of all this water, I concluded that the seal wasn't properly sealing the glass panel, and therefore well could be the source of the whistles when there is a pressure difference between the air in the cabin and the air above the roof.
The rubber seal wasn't damaged at all, in fact it looked like new. Also, it still fitted perfectly well in the groove of the glass panel.

So I decided to re-seal the rubber seal to the glass panel using some type of liquid sealant. I ended up using the bottle of "Gleitmittel", G 052 172, which looked like to be viscous enough to both seal and maintain the rubber. I generously wetted both groove and rubber seal to re-apply the seal in its groove. 
Well, the result is amazing!  No more whistles, at any speed up to 160 km/h. It is noise free now since a week. But if the noise ever returns, I will sure use silicone kit to kill it forever.

Willem


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## PanEuropean (Nov 3, 2001)

Hi Willem: 

Thanks for the great write-up, much appreciated. 

I have re-hosted the photos in my post from 2008, above. 

Michael


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## WillemBal (Nov 20, 2010)

PanEuropean said:


> Hi Willem:
> Thanks for the great write-up, much appreciated.
> Michael


 You’re most welcome. When I read your reply, I realized that I hadn’t posted any pictures, so here they are: 










The solar roof panel, removed from the car. 










The roof panel from the inside. One difference with the standard sunroof is that provisions have been made to allow electrical contact with the car when the panel is closed or tilted. The other difference is that the trim panel, covering the bottom side of the panel, is not motorized. Instead, it is attached semi-permanently to the solar panel by means of a retaining clip. The trim panel can be detached from the solar panel from the inside by opening the roof half way, then grab the trim panel in the middle and pull it slightly forward and down. It then unlatches from the retaining clip and can be moved all the way aft by hand. 










A close-up of the inverter/converter. Its role is to adapt the output impedance of the 28 solar cells to the voltage/current needs of the fan. The fan already starts turning at 2 Volts (a weak sun or clouded sky already makes the fan run). On a bright sunny day, the fan spins with about half the maximum speed. 










A close-up of the spring loaded contact on the solar panel. It makes contact with the sliding contact block on the car body when the roof is closed or in the tilt position. 










This photo shows one of the two contact blocks which are permanently attached to the car. It also shows the mounting rail in which the mounting bracket of the left side of the panel slides in to. 










This is the right side, seen from another angle. 










The rubber seal, detached from the sunroof panel. When I removed it, a lot of water came out of the groove in which it was fitted as well from the hollow inside of the seal itself. 










A close-up of the rubber seal. Note the hole in the part which is supposed to face the bottom side of the panel. There are about 12 of them and their function is, I think, to drain the water which may intrude via the rear side of the seal, where the two ends are partly bonded together. 

The cause of my wind noise problem must have been related to the water ingress in the seal itself or the presence of the water between the seal and the panel. I had adjusted the panel already many time, each time carefully checking the height differences between panel and the adjacent roof. Lubricating the inner part of the seal seems to have done the trick. I’m glad about this, as I was already thinking about replacing the rubber seal, which is very expensive. About 200 Euro for just the seal seems like daylight robbery. 

Willem


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