Repair-It

Oh yes. Soaked pass side floor and even the rear pass side. Very heavy rain in the last 24-48 hours. I did adjust the sunroof a few weeks back and I know that softball dent makes the sheetmetal funny in the front right corner. But I did some research and that lead me to look at the sunroof drains. I've actually never had the pleasure of a car with clogged sunroof drains (and not that many with sunroofs). So this would be exciting. For the record, I am aware that clogged sunroof drains are a very common thing.

Brief education: all cars as far as I know have a tray that collects water if any leaks past the sunroof seal. At all 4 corners of this tray, there are drains and lines that run the water out to the ground. They can get clogged, or other annoying things can happen.

To first determine if they were even functioning I filled up an old water jug and got a funnel. I poured the water into the tray at the front right and before I got very far it was obvious the water wasn't draining at all! Didn't expect to find an issue that quickly but yeah, it wasn't draining.

I looked up various techniques for clearing them. Compressed air is not recommended as it can cause the hose to come off the nipple at the tray and then you get to pull the headliner to fix that. A Cadillac forum post suggested this dryer vent brush which I ordered but is a week out, probably because slow boat from China, despite 2 day prime.

https://www.amazon.com/COBRA-PRODUCTS-T ... vent+brush

You cut off the brush and make sure the nut on the end is ground smooth and shove it into the hose. It apparently has the right properties to be stiff but flexible, and not too big or too small. Not satisfied with my week wait, I looked all over for my fish tape and couldn't find it. Probably too stiff anyway. I found some trimmer string though, and some folks had luck with the big stuff. I didn't have the big stuff so I tried it anyway.

I couldn't get it to thread all the way in, and even stuck it in the end of my right angle drill. I wanted to find out where the drain actually exits so I needed to get water out the left drain, assuming it worked. I had to jack up the right side of the car so water would go that way. And it did. And I found the drain. It is actually halfway down the front door hinge area of the body, taking the shape of a big rubber grommet with a small hole in the middle where the water comes out. Cool.

So back on the pass side, I tried shoving my trimmer string into the drain hole at the door. It went in a little and kind of stopped. But then water started dripping! I messed around with it more and all of a sudden water began gushing out. Holy crap I dislodged the junk.
This pic does not show the gushing by the way. When I say gushing, I mean a straight jet of water that hits the door itself. The other end at the tray. And I realized the driver's side was quite clogged, as well, because it only dribbled. These things move a surprising amount of water. I rinsed it more until it seemed good and then did the other side which took the same screwing around at the drain with the trimmer string. Eventually that one freed up, too! So now both front ones seem good. I have no idea where the rear drain holes are in the sunroof tray.

However, in rinsing the tray I guess I got a little too excited with it and ended up overflowing the tray (I think) and water was running out of my overhead console and all over the shifter and a little on the HVAC controls. It was pouring through the onstar mics, the sunroof switches and the homelink buttons. And around the console itself where it meets the headliner. Noooooo!!!

More cleanup. I took the car on a drive and tried cornering to slosh the water out of that overhead console area and that was a mistake. Water sloshed alright - the whole car seemed to reboot (gauges, HVAC, nav) and it said service engine soon. Goddamnit. I drove the rest of the way home without aggressive cornering and everything was fine. I have idled it with the heat and A/C cranking for 45 minutes and just started on another hour of idling. Water is bad and I hope stuff dries out. I also hope I fixed the original leak issue. I wish I just didn't get so aggressive pouring water into that tray.

Sucks. Thankfully the big-ass Ultraview on the SRX doesn't leak and neither does the CTS-V. Though some guys suggest yearly drain line clearing just to keep it clear. The Maxima also didn't leak.

That sucks. Hopefully everything is good once it dries.

I just shut it off. It was hot in there. Floors are much drier but still damp. Hopefully other stuff dried out.

Oh yeah, when I had the doors open doing the drain cleaning and stuff, it wouldn't crank after, just like after I vacuumed. I think this battery is very marginal.

kevm14 wrote: Though some guys suggest yearly drain line clearing just to keep it clear.

Anyway, there is a large tree in my yard and during the spring both my vehicles get covered in yellow pollen. Apparently, the pollen is small enough to get past the seals and clog the drainage lines every year causing this problem.

Last year I took the car to the Cadillac Dealership and they cleaned the drainage hoses. (Problem Solved) But this is quickly becoming an costly expense to do this every year.

Maybe this is what did it. It got plenty of junk from trees and some caterpillars this spring. The other two cars with sunroofs are garaged.

kevm14 wrote:I have no idea where the rear drain holes are in the sunroof tray.

They are at the rear corners but those are completely obscured by the roof since the tray has to accommodate an open sunroof. Anyway, the consensus seems to be to remove the trunk side carpet stuff and disconnect the hose from the body grommet and rod it out from the bottom. That's probably where it is clogged anyway (if it is clogged) if the front is anything to go by. And that makes sense - junk would flow down hill before getting stuck right?

Drove it to pick up my remaining juniper and everything seemed normal. Maybe when my dryer vent brush comes in next week I'll modify it and rod out the rear drains to make sure they are clear. I will pull the front up on ramps for the water test I guess. Or maybe I can just turn it around where it is parked now for enough of a slope. Not sure yet.

Here is the official FSM procedure for cleaning the drain lines. I was hoping for a diagram.

They say use low pressure compressed air. I wonder how many techs just blew it out with the full pressure and then made the customer pay for headliner removal and hose reattachment.

Maybe worth an update. It rained pretty hard on, uh, Saturday I think. Interior and headliner was dry. I still haven't tried to clear the rear drains or even test if they flow. I should still do that but I am relieved that the flooding issue seems to be fixed.

Guess what.

It rained really hard this morning. I got a flash flood warning through CodeRED so yeah. Even have a leak in the great room. Fantastic.

Decided to run out to Lowes to look at cabinet hardware. Made it about a mile and the headliner/switch/overhead console area of the STS started dripping. Nooo!! Almost exactly 1 year later, too.

For the record there was a ton of organic matter on the STS this spring season and I thought to myself...I may want to flush the sunroof drains since it caused a problem last year. Never got around to it. Figures.

So I got my trimmer line and in the pouring rain I stabbed the front drains and the passenger side one was definitely gummed up with some junk that I could see after I opened the door. I got it free and water came pouring out, just like last time.

I do have a theory. The PO told me the dent at the front right roof at the edge of the sunroof was from a baseball. Well I think it actually effects the seal and maybe more junk gets in there or something.

In any event, I need to do this cleaning annually.

The pollen has been bothering my nose so I figured it was time to flush the drains. Sure enough, they were clogging. In fact I got a little overzealous flushing the lines and got some water through the overhead panel (lights, sunroof switch, phone mics). Came out going around corners on my way to look at the STS-V. That was nice to get rained on. Eventually it stopped.

But yeah this really does need to be done annually. I flushed with water and had to poke at the drains with my weed whacker string and it takes a while until the flow is what it should be. I even had to move the car so the driver's side would be lower because it was all flowing to the passenger side until I did that.

Tools are a small funnel, a gallon of water and string from a trimmer.