[VegasWagon]

I had a water leak in the roof of my CTS wagon which appeared at the right rear of the headliner (above C & D pillars). After looking online it appeared to be most likely coming from a clogged rear sunroof drain. I tried to clear it with trimmer line, but it didn't solve the problem. I didn't see any signs of leaking in the sunroof seal either (which would have been expensive to replace). So I dropped the headliner on the right side to see if I could locate the source. No water showed when I poured a waterbottle over the sunroof, or even when i poured in the sunroof tracks. However, i did notice water coming in when the water came across to the roof rails (for the roof rack). I don't have a roof rack, so the metal side rails are just covered with the t shaped rubber molding. There was no obvious damage to this molding, but i pulled it up and tried pouring water in the track. This also did not show a leak. It appears that water coming off the roof was going down between the body and the metal rail and was not draining, but escaping through a broken pinch weld of some sort

I tried a temporary solution by running a bead of caulk along this line. It doesn't show at all when covered, and I have no more leaks.

Has anyone else experienced this? Is there a more permanent repair? Do I need to replace my molding?

dropping the headliner was not as bad as I expected, but I did have a few tips.
Having a trim panel remover was key. Also, there are two clips at the rear of the headliner for which the mounting point is just hot glued to the headliner. Be very careful to pull straight down only so as not to break off a mounting point.

And folex works wonders to remove water stains.

 

[redheadedrod]

What year? Prior to 2012 they have the same leak as the sedans. My 2012 wagon doesn't have the restrictions in the end.

There is a thread on how to repair this issue if you search for it.

Rodney

 

[tinman]

You still need to remove the little restrictions at the end of your sunroof drains. This is a must. Search for thundercad thread 'stop the insanity'.

 

[VegasWagon]

Thanks for the comments. It appears that the problem wasn't in the sunroof drains. I poured water directly onto the sunroof, no leaks. I opened the sunroof and poured water into the sunroof opening, no leaks, and draining as it should in wheelwells.

The issue is that when the water was poured into the roof rails (metal track covered by rubber, that you use to mount the cross bars) it would leak. See gap in red on first attached photo. I tried running silicone between the body and the track, and this mostly got rid of the leak (see attached photo), then last week it happened again (not as bad, only in one spot above d pillar).

i wonder if the leak is in one of the holes in the track (circled in blue), but obviously this can't be completely closed as the water needs to drain.

So do these holes drain into the sunroof drains? any tips on cleaning these out?

Any suggestions on what to do next?

 

[tinman]

I believe those holes are what the crossbars anchor into. There has to be another answer that I don't have.

 

[redheadedrod]

Make repairs to the sunroof drains first... See if issue goes away. Will be a bit of a pain accessing the drivers side but you really need to start there. There should be no way for the rails to leak through unless something was damaged. Mine only have one of those holes per side but I don't even have the rubber on my rails with the bike rack mounted there. Those rails are riveted to the roof and if there is a leak somewhere from those rails the vehicle must have been in an accident that wasn't repaired properly or some other issue such as rusted through hole or something that you can't see.

I strongly suspect it is the drains on your car. If you want to see otherwise you may have to drop the headliner and pour water on the rails and see where it is coming through and end up having to fix from underneath. You may find it easiest to drop the headliner by the rear lift gate and look there.

Rodney

 

[PipeNSlippers]

Make repairs to the sunroof drains first... See if issue goes away. Will be a bit of a pain accessing the drivers side but you really need to start there. There should be no way for the rails to leak through unless something was damaged. Mine only have one of those holes per side but I don't even have the rubber on my rails with the bike rack mounted there. Those rails are riveted to the roof and if there is a leak somewhere from those rails the vehicle must have been in an accident that wasn't repaired properly or some other issue such as rusted through hole or something that you can't see.

I strongly suspect it is the drains on your car. If you want to see otherwise you may have to drop the headliner and pour water on the rails and see where it is coming through and end up having to fix from underneath. You may find it easiest to drop the headliner by the rear lift gate and look there.

Rodney

I was fixing my blocked sunroof drains on my 2010 CTS wagon.
This video is very good for the front drain pipes:

The left rear drain can be accessed through the battery compartment (you can pull out the green pipe in front of the battery inserted into a grommet in the wheel arch)
The right hand side can be accessed by removing the rear wheel liner.
You will see a big grommet with a cable coming out towards the upper rear of the wheel arch. Pull the whole grommet out and you will see the pipe inserted into the back of it. Make sure you scoop out all the muck inside the grommet where the pipe was inserted and run a weed whacked line up the drain pipe. Both were full of muck.
You can undo the four bolts holding the rear stationary sunroof to gain access to the drain holes and slide it an inch forward out of the way. No need to drop the roof lining.