PSA: Clean your sunroof drains

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2006 Lexus ES330, but this applies to all cars with sunroofs.

I was doing a ton of work to this vehicle. At the end, prior to delivery, I washed the vehicle and found an active water leak from the passenger side A-Pillar.

Upon further inspection I found the sunroof drains to be completely clogged. Luckily I found the issue before rainy season and resolved it. Otherwise, this water leak could have caused serious damage to the carpet and interior wiring harnesses.

Before:
IMG_0556.webp

IMG_0557.webp


After:
IMG_0558.webp

IMG_0559.webp


I also cleaned and lubricated the sunroof tracks. The sunroof is now sliding very quietly.

IMG_0563.webp

IMG_0561.webp


Again, I highly recommend performing this service annually (some OEM’s even list this on their maintenance schedule) to prevent a water intrusion disaster.
 
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Looks like the drain inlets were obviously gummed up with crud.

Any idea if the drains are OK now that you've cleared the inlet? Did you test the drains after work was done? I ask because my greatest fear with my drains is that they'll clog somewhere downstream in the tube itself, and it'll be darn near improbable to get them cleared out.
 
Sunroofs also have drains in the back on both sided. Most are way to hard to access from the top. They usually terminate at the back wheel-well. Sometimes behind a piece of plastic wheel-well trim. You can snake those tubes with an appropriate od wire or plastic tubbing to clean the sun roof drain tubbing out.
 
Looks like the drain inlets were obviously gummed up with crud.

Any idea if the drains are OK now that you've cleared the inlet? Did you test the drains after work was done? I ask because my greatest fear with my drains is that they'll clog somewhere downstream in the tube itself, and it'll be darn near improbable to get them cleared out.
I always recommend suction instead of (tempting) compressed air to clear drains.

Shop vac at the top to suck out what you can then run trimmer line a few times followed by flushing with water.
 
Looks like the drain inlets were obviously gummed up with crud.

Any idea if the drains are OK now that you've cleared the inlet? Did you test the drains after work was done? I ask because my greatest fear with my drains is that they'll clog somewhere downstream in the tube itself, and it'll be darn near improbable to get them cleared out.

THIS………^^^^^^^
 
Absolutely! I use compressed air once a week, but I got this nice, long brush that goes all the way down the drains that I use every couple of months.
 
How did you clean it?

Looks like the drain inlets were obviously gummed up with crud.

Any idea if the drains are OK now that you've cleared the inlet? Did you test the drains after work was done? I ask because my greatest fear with my drains is that they'll clog somewhere downstream in the tube itself, and it'll be darn near improbable to get them cleared out.

Vacuumed as much as possible, followed by wet paper towels to wipe up the sludge. Then degreaser and a detailing brush, followed by pouring 1-2 qt of water down each drain hole. Finished up with snaking some weed whacker wire down each of the front holes to ensure that they’re clear.
 
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How did you clean it?
If there's a clog from debris like leaves and needles I use a flexible cable like a long bicycle brake or shifter cable (with the housing) like a snake. Mechanics used to use old tachometer cables for that purpose before those finally disappeared. You could also use catheter tubing size 14-16 FR. That's the same size doctors and nurses likely shove up your... If you use tubing for rooting in the drain you can even irrigate and flush while rooting around. Headlight housings also have drains. If you frequently park in wooded areas you may want to clean those drains regularly, too. If the headlight housing is not properly aspirated you may see internal fogging.
 
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I recommend you don't use compressed air as it can cause the hose to detach from the metal nipple. If it does detach you'll need to remove the head liner and perhaps other pieces of the interior to reattach the hose.
 
My daughters CRV was leaking on to floor on passengers side. Sunroof rarely used but I clean all around at least 2x per year.

Digging further on hers the drain was clogged where it exits into wheel well. The entire area was full of leaves dirt etc that made it's way behind the liner. Hers also has a 90 degree elbow at the end so you can't trimmer line all the way through. I ended up with shop vac at the drain side to get totally cleared. Part of my semi annual cleaning incudes a 16oz water bottle down each corner in her CRV and wife's Pilot and make sure it drains fast.

Had another small water issue in CRV but I believe was from the melting snow/rain and then cold days freezing stuff there. Haven't been able to reproduce that.

I didn't get the full of leaves picture but top rubber piece next to cable is the drain on drivers side. The blue tube behind wire harness is drain tube on inside that goes to the elbow. Other cars probably different but an idea of what to look for.

This was drivers side outer drain/fender that hadn't clogged yet, not as full of leaves.

CRV drain 1.webp
CRV drain 2.webp
CRV drain 7.webp
CRV drain 4.webp
 
Just be careful pushing brushes and lines down the tubes. You can potentially cut the drain tube or push it off the sunroof track fitting. Then you've got big problems.

It's a shame nobody makes a "Drain-O" style product that's safe for sunroof drain tubes. That would be the cat's meow.
 
Man, this is a good reminder! I’ll check the sunroof drains on the Sienna here soon. Our van before it didn’t have a sunroof so I forgot about doing this to be honest. I’ll bet it might need some cleaning. My wife parks it under trees at work and it’s always getting sap and leafs all over it. I have repeatedly asked her to park elsewhere, but the closest spots to the entrance are all under large trees. She won’t stop. Like most people she doesn’t alter her life or habits to suit a machine. It is what it is.
 
2006 Lexus ES330, but this applies to all cars with sunroofs.

I was doing a ton of work to this vehicle. At the end, prior to delivery, I washed the vehicle and found an active water leak from the passenger side A-Pillar.

Upon further inspection I found the sunroof drains to be completely clogged. Luckily I found the issue before rainy season and resolved it. Otherwise, this water leak could have caused serious damage to the carpet and interior wiring harnesses.

Before:
View attachment 249835
View attachment 249836

After:
View attachment 249837
View attachment 249838

I also cleaned and lubricated the sunroof tracks. The sunroof is now sliding very quietly.

View attachment 249839
View attachment 249840

Again, I highly recommend performing this service annually (some OEM’s even list this on their maintenance schedule) to prevent a water intrusion disaster.
Great job, you found and saved yourself a huge headache. Hopefully someone paying attention also. Had leaks coming down the front side of my pillar internally on my sold 08 Acura TL. Hence, totally clogged like your one but both of mine. Cleaned them all out good/lubricated and was good as new.
 
There are drains other than sunroof drains on vehicles that should be checked and cleaned if they are not free-flowing. I already mentioned headlight drains/ventilation. There are usually drains around the trunk and under the cowl, often near the shock towers. These drains drain into the wheel wells, often behind the fender liners. On some cars leaves and mud commonly fill up the space between the wheel well and the fender liner. That's an ideal breeding ground for rust. Doors also have drains in the bottom and they should be also checked and cleared. The door panels get internally wet every time it rains or when you wash the car. If the water doesn't drain the doors rust out from the bottom up. The trunk has usually a drain in the spare tire cubby.
 
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