Once autumn arrives, the first water infiltrations on the panoramic sunroofs occur.
We’re going to look at the various causes of these problems, which threaten to turn your car into a veritable swimming pool, which in turn is bound to give your car a nasty damp smell.
We’ll also look at solutions for isolating and solving the problem.
Are your front and/or rear pillars damp or even soaked? your carpet is soaked? is your trunk flooded?
The following should help you solve the problem of water seepage from your panoramic sunroof.
Diagnosis
To carry out the diagnosis, the canopy must be removed, and the roof tested for watertightness.
First, pour in some water to see if it’s draining properly down the drain pipes.
Next, you’ll need to plug the 4 drains in the sunroof, then fill the sunroof with water to test and see where the water will drip from.
The ideal time for this test is around 24 hours, but it can be carried out during the day.
Once this test has been carried out, you’ll have a good idea of where the leaks are, which will make troubleshooting easier.
We’ll now look at the various causes of leakage.
1 – Clogged drain pipes
You can read the article I wrote on this subject:
2 – Drain pipes out of order
You can read the article I wrote on this subject:
3 – Seepage through the inner joint
You can find the gasket on the website or at a VW dealer.
In some cases, the inner gasket (1) may have deteriorated, allowing water to seep into your car.
It’s easy enough to spot this problem, as the contours of the joint are very visible.
Walk around to see where water is penetrating.
Ideally, you can replace it or seal it with silicone.
4 – Seepage through the outer seal
You can find the gasket on the website or at a VW dealer.
The outer gasket (4) is the seal between the body and the sunroof unit. It is visible from outside the car.
This gasket has a lip which is sandwiched between the sunroof block and the lower part of the body. The sunroof block clamps the lip to the lower part of the body.
Sometimes the lip comes out for unknown reasons. To put it back in place, you’ll need to remove the entire canopy, first to locate the leak and then to solve the problem.
Once the canopy has been removed, you’ll need to remove the screws holding the sunroof assembly in place all round.
You can change the seal if necessary.
The joints have a self-adhesive part which facilitates installation. However, care must be taken not to over-tension the joint during installation, nor vice versa.
5 – Areas of the sunroof unit where seepage can occur
When you disassemble the sunroof assembly, you’ll see where the plastic and metal parts are joined. There’s a little black silicone mesh to ensure a watertight seal.
Sometimes this is not enough, as was the case for the front right.
Exactly at the junction of the two parts of the sunroof frame, which resulted in a drip leak (see photo) that flooded the ground and ran down the front right-hand side of my vehicle. The carpets and foam underneath were soaked with water.
So I dismantled the roof frame and reinstalled the gasket as it should be. Then I added a small strip of silicone covering a little more surface area. see photo sorry it’s a bit dirty.
6 – Cracked sunroof frame
If you detect a cracked spot on your sunroof frame, then your roof frame is cracked.
This is probably the most restrictive cause of infiltration, since in many cases it requires the sunroof frame to be replaced.
However, there is one last hope that will save you from selling an organ to finance the replacement of your roof frame.
Once you’ve completely dismantled your roof frame, you can make a last-ditch attempt to seal the crack from the top using wet-zone sealant (pool, boat).
Make sure it’s watertight before refitting the sunroof unit.
7 – Infiltration through the rear light
Be sure to check this before undertaking the time-consuming disassembly of the headliner or roof frame.
It’s not related to the sunroof, but this fault could suggest infiltration through the panoramic sunroof, which is not the case.
Occasionally, water seeps in through one of the rear lights, flooding the same areas as when it seeps through the panoramic roof.
In this case, replacing the headlight would be one of the suggested solutions, or the good old sealant.
8 – Infiltration through roof bar seals
Infiltration through the roof bars is not very common, but water can sometimes seep through the roof bar fixing screws.
You can change the roof bar seals or use silicone sealant.
Here’s the article I wrote about it:
You had infiltrations that you solved say it in the comments
