GAsc300

Hello

After doing an oil change on my 1993 SC300, I took a test drive and heavy rain fell. I surmised my sunroof drain lines were clogged as water dripped in down the driver and passenger pillars, dripped out of the map light, and leaked onto top of back seat. Super annoying.

It’s happened before a few years ago and I’ve always had trouble cleaning the rear drain lines. This time I did a better job and though I’d share what I did.

if you open the sunroof and look down at the
black plastic housing (?) from above you can see circular drain lines in the front corners. On the other side of these drain holes is attached a plastic hose (1/4 inch diameter or so) through which water drains. These lines can be best cleaned with wire or weed wacker line of 1-2 mm thickness and maybe 5 feet long. Gently guide it down the drain line and twist and turn it a bit. Most likely this will loosen the clog. Park car on hill facing downward and pour few ounces of water down each side and check that it runs down the drain line and exits car behind front wheels.

The rears drain holes are back there in the rear corners of sunroof housing but can’t be seen so can’t easily be cleaned. This time I was determined to see the rear drain lines. I sat in the back seat and pulled the headliner off it’s rear clips to do so.
I observed that the back of the headliner is held onto roof with plastic clips (4?) that fit into slots in the metal roof. These are about 2-4 inches from the back of the headliner. The clips are attached to thin metal brackets that are glued to headliner. So the headliner isn’t glued directly to roof, but rather, held in place by these clips plus some aluminum screen things toward center of roof that act like Velcro. I only took off the rear clips and messed with the first 10 inches of the headliner.

When I got the back of the headliner unclipped from the roof I could see the back of the sunroof housing and the rear drain lines. It’s a tight fit in the back seat and my photo is too close up but that’s all I could do. See below:


I’m sitting in rear passenger seat lookin up at roof after pulling headliner back. In this photo I have disconnected the rear drain line and have a metal wire running through it. My car is maroon and you see the bottom of my roof, rear part of the black plastic housing of the sunroof, and the disconnected drain line that starts here and runs downs 4 feet or so to drain out behind the passenger rear wheel, technically exiting out of a tube in the rear quarter panel behind the wheel.

My passenger side rear line was clogged and my driver’s side rear line was disconnected completely. So when the rear driver’s side line drained, it drained into the back of my headliner. For how long, who knows.

here is a photo of where the rear drain line exit the car being the rear wheel:


This is behind my rear driver side tire looking up under the rear quarter panel (if that’s technically the name of the piece). In the lower left you should see a rubber tube and inch or so long. This is where water exits from the rear sunroof drain line. The drain line tubing attaches to this rubber tube on the other side of this panel. Possibly you could attempt to unclog the rear line starting here and going up with a wire but that wouldn’t tell you if your upper line was disconnected as mine was.

Good luck when and if your sunroof drain lines clog. Hope this post helps a bit. If you don’t park under trees that drop debris, it’ll probably never clog. I’ve got a two car garage but my SC doesn’t get to use it.

—gaSC300 (Georgia SC300)

t2d2

iTrader: (8)

Those rear drains do seem impossible to access, even if you take the sunroof glass out. You may be right that dropping the headliner is the only way to do so from above (as opposed to from below via the drain exits), but be warned that the headliner's attachment points are pretty fragile and probably won't handle being removed many times. You may be able to glue the tabs back on when they rip.

GAsc300

Hey there, t2d2

thx for reply. For me, one problem helped me solve another. My headliner in rear was sagging due to those attachment points having come unglued. I had ordered some 3m headliner adhesive stuff to fix if … the sagging let me easily see and solve sunroof rear drain problem.