I thought I'd share a guide with whoever is having this problem, as I've seen a few complaints about it.
It all started when I bought my Megane Sport Tourer Oasis with a Pan-roof. I started a thread about the whistling sunroof, as it whistled at Motorway speeds making for a very annoying & stressful journey. Plus, the windier it was, the slower I had to go to avoid the noise!
I got some great advice which was to use Silicone Grease to rejuvenate the sunroof seals, but unfortunately you can only get easy access to the front half of the main sunroof seal.
I greased this front half which did make a difference, but the noise was definately still present - so here's how to get rid completely:
- Firstly, you will need some Silicone Grease - I got mine from Maplin for £3.99.
- Open the sunroof fully, and apply a coating with your finger around the front half of the main sunroof seal.
- Close and open the sunroof a few times, to make sure that the grease is making good contact with the glass to ensure a good seal. Apply more grease if needed.
(The next steps may differ slightly for different models, as I did this on my Sport Tourer which has permanent Longitudinal Roof Bars - if you have the hatchback or Scenic, just ignore the roof bars removal step).
- Remove the longitudinal roofbars (if you have them) by:
Firstly unclipping the little holes on top. I used a very small flat screwdriver (from a spectacle repair kit). Be careful as they are easily scratched.
Then, undo the large torx bolts (3 on each bar).
The bars can then be lifted out and off.
- Then, you need to remove the black plastic strips in the roof (if you have them).
- To do this, you need to start with the back ones by doing the following with each side; With quite a bit of force needed, slide the strip out backwards (opening the boot may help).
- Then, undo the torx bolt revealed, which holds the next black strip in place - this strip is the one that guides the trailing edge of the sunroof along the top of the car when you open it.
- Ensure that the sunroof is open fully, and then slide that strip out backwards by about an inch or two (needs force again) and, whilst holding the back of the sunroof up, remove the strip.
- You can then carefully rest the trailing edge of the sunroof on the roof itself.
- You can remove the glass fully if you want by undoing the bolts/connections at the front, but for the purposes of this fix you don't need to.
- Carefully lift the trailing edge of the sunroof up enough to fit your arm underneath, and apply silicone grease to the remaining half of the main seal.
- Once you are happy that the seal is sufficiently covered (do not close the sunroof to test!) you can replace all the parts removed.
- In order to re-fit the plastic strips that hold the sunroof in place, you need to make sure that the little sunroof feet go into the runner slots in each of the strips.
- Then for each side, bring your level of sight down to the top of the roof and guide the strip into the retainer on the roof.
- Slide into place and refit the torx bolts.
- Re-fit all other bits by reversing the steps above.
Once it's all been put back together, open and close the sunroof a few times. It may stick a bit at first but will then be fine.
Then, go on the motorway and enjoy a quiet ride!!
Please feel free to add to this guide or add additional steps for different models - I think this wil help quite a few people.