One time i'm faced this type of problem which you have written. Than i found a solution threw a another person. I am sending you that words which he suggest me....
Read this:
The most common cause of leaks in the Ion/cobalt is the sunroof. The sunroof has 4 drains, one on every corner. On each of these corners is a small hole, with a rubber tube attached to it. This rubber hose runs down the pillars to the outside of the vehicle. This allows any water that builds up in the sunroof tracks to drain easily and not flow or pour over into the vehicle.
Typically when you have a leak there are 2 problems. The most common is that one of the tubes has popped off. This is very easy to fix and we'll be covering this first today. The second most common is that one of the tubes is clogged. This typically happens because of dirt and grime has built up around the drain hole, and during a heavy rain all this grime gets washed down the hole and blocks it up.
The blue arrow is pointing to where the hole is. Notice all the crap built up around it? Were going to be taking care of this and securing the drain tubes.
You want to start by taking off the driver side A-pillar. It attached by 1 7mm bolt. Remove the plastic tab about halfway down the pillar and remove this bolt. Then pull on the top of the pillar and it should come loose.
Then remove the visor. There are 2 phillips head screws holding the left side on and 1 on the right.
Once you remove the visor you can lightly pull down on the headliner, but only pull on the corner your working on, you dont want to crease the headliner.
If your reading this, you probobly have a leak, and this is what you typically will see.
Just re-insert the tube. Then wrap 2 zipties around where the large piece of the tube connects and on the small piece like so.
If done correctly, you should be able to lightly tug on the tube and it wont slide out.
Now re-setup the headliner, re-install the visor, and install the a-pillar.
Now, unfortunately, I had already done this on the other 3 corners of the car, so I dont have pictures for you to follow, but the pass side and both the rear corners are just as easy to get to (easier I think because of my gauge pod ). Plus the rear uses the same size bolts and all.
The second part of this how-to covers clogged drain tubes. When repairing water leaks, most saturn techs do not do this part. I do it everytime. Getting ******, nasty water backed up and pouring down on your nice seats would totally irritate me, especially if I had the problem fixed already, so I always make sure to do this part.
The bottom part of the drain tubes run down the a-pillar and out of the car through a grommet, pictured below.
Getting to it is not very easy. You have to remove the plastic trim that runs along the bottom of the door along the carpet, referred to by GM as the "carpet retainer". Once removed, pull the carpet in whatever corner your working in back, along with the sound deadening material. Next, reach up high along the inside edge, past the wiring harnesses and all, and pull the rubber insulator piece out. If your working on the driver side it will be on the left about half a foot up off the carpet. Its tucked into the frame. same on the right side. Once you pull that out, you should be able to reach into the hole where the insulator piece was and feel the drain hose. pull it out of the grommet, then pull the grommet out.
Next, take a pair of scissors or something sharp, and clip the end off like so.
This will allow any grime, dirt, and other random crap to drain out, instead of filling the tube up and causing a leak. Here's proof that this is the cause. This came out of the grommet when I removed it from the car and spilled on me. smells bad too :\
After clipping the grommet off, reach back up into the car and re-insert it into the hole in the frame.
I cannot stress this enough, DO NOT LET GO OF IT. Unless your made of rubber you will not be able to reach it again. You will have to buy a new one or come up with some other way of routing the drain hose. I lost one grommet and a pair of pliers before I realized how far down into the frame that hole reached. DO NOT LET GO OF THE GROMMET.
If you do, you could always make the drain tube longer so it's not draining onto the floor.
The rear is MUCH easier. Pull the carpet on either side away and you should see this.
Remove the grommet and pull the tube out, clip the end, and re-insert. Just like the front, but easy!
Now for the test! Get a bottle of water or something, and pour it into the drain holes in the sunroof, in each corner. Pour carefully! If you spill it will go in the car! If done correctly you should see this...
Behind the front wheels on the ground you should see water draining out, same with behind the rear wheels. When I did mine I could see quite a bit of crap coming out with it.
If your still experiencing a clog somewhere, find some pressurized air. Working in a shop this is easy for me to find, but you may want to try just pulling one of the drain tubes and blowing into the end of it. This should push whatever bit of crap is stuck in the tube out.
If that does not work, your last resort is replacing the tube all-together. But this should be a last ditch effort and should not be necessary.
Have a nice day! I fell it will possible to you.......
