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Clearing sunroof drains with Drano

9558 Views 11 Replies 6 Participants Last post by  markismail
I saw this on YouTube. A guy named Nestor did it so I give him all the credit. I had water on the floorboard behind my driver’s seat in my 2014 Altima. Two mechanics tried blowing out the lines with compressed air, but apparently neither one of them bothered to test whether the drains were actually clear.
I bought a $5 bottle of two-part drain cleaner and a turkey baster. I had about 3 feet of 3/8” (?) hose that fit snugly on the tip of the turkey baster. I sucked up the first liquid and put a dose at each corner, using the tubing to get way back to the rear drain holes. I rinsed out the tubing then did the same with the second liquid. I waited about 45 minutes (directions say 1 hour) and poured a little really hot water into each track. Voila! Water drained from all four corners. Never disassembled any part of the car.
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Drano is a bit extreme. Most sunroof clogs are a combination of tree sap and mud, so bug-splat remover usually works well and won't take the paint off the inside of your fenderwells. You also need to be careful that the leak isn't because of a disconnected hose. If that's the case, Drano inside the headliner or on the carpet at the firewall could be very unpleasant!
I saw this on YouTube. A guy named Nestor did it so I give him all the credit. I had water on the floorboard behind my driver’s seat in my 2014 Altima. Two mechanics tried blowing out the lines with compressed air, but apparently neither one of them bothered to test whether the drains were actually clear.
What has worked for me to clean out those drain tubes is to use an old time speedometer cable, which you can buy at an auto parts store. The cable is very thin and it won't flex/twist; it's about 48" long so it should cover the full length of the drain tube.
Thanks for the tips on the bug remover. Don't use Drano. The car reeked of a chemical smell afterwards, so I poured more hot water and really flushed the sunroof perimeter area good and wiped it down with a paper towel. I also drove around a bit with the sunroof and all the windows opened. And the trunk reeked as well, so I had to let that air out. This is probably a bad idea and I got lucky that I didn't have a disconnected tube somewhere in the walls of my vehicle. I tried the grass trimmer line trick but could not figure out how I was supposed to get to the rear drain hole in the sunroof area. And I never found the outlet holes under the car.
If you have access to compressed air or need to use a snake, the rears on most sedans are easier to clean out from the bottom-up than the top-down. The hoses usually exit via a "through-hull" fitting behind the rear wheel hump, so on sedans you generally just need to push aside the interior covering to get at them. Much easier than dropping the headliner, or trying to snake into the hole with a flashlight and your head squashed against the roof. Just pop the hose loose from the bottom nipple and blow or snake it out the top, then use a small screwdriver to make sure the through-hull fitting isn't obstructed.
PS - The outlet holes are almost always underneath the wheel-well coverings, so looking for them on the outside is usually a vain exercise unless you lift the car and peel back the inside covers.
PS - The outlet holes are almost always underneath the wheel-well coverings, so looking for them on the outside is usually a vain exercise unless you lift the car and peel back the inside covers.
I had two different auto shops try this. It failed both times. Apparently neither shop thought to test their results by pouring water in the sunroof to see if it drained.
Sadly, it's amazing how many shops simply don't know or use the right methods and tools for sunroof service. Personally, I don't get it -- it isn't as if sunroof plumbing is rocket science! Fortunately, for anyone who's the least bit handy, once you understand how the system is constructed it's very easy to resolve common problems for yourself.
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Both of my rear drains were clogged on my '09 coupe. I ended up dropping the headliner in the back, and ended up installing new clear hoses to the drains behind the rear wheel wells. The job was a royal pain in the a$$! I had found the old lines had several kinks in them, probably from the factory I'm sure. At any rate it worked but it would be MUCH easier with someone fishing the line through from inside the car to the trunk area.
Yep, drains on the coupe are a particular PIA to replace. However, they're still easier to blow or snake clear from inside the trunk than dropping the headliner. Bottom-up is almost always easier than top-down when it comes to rear drains on sedans and coupes. Only SUV's and hatchbacks are often a different story, because the luggage room trim on many of them is a bigger PIA than the headliner..
Both of my rear drains were clogged on my '09 coupe. I ended up dropping the headliner in the back, and ended up installing new clear hoses to the drains behind the rear wheel wells. The job was a royal pain in the a$$! I had found the old lines had several kinks in them, probably from the factory I'm sure. At any rate it worked but it would be MUCH easier with someone fishing the line through from inside the car to the trunk area.
Totally agree with you!! My 2008 Coupe had a kink on each side in the rear pillars where Nissan had assembled the car with both sides pinched by the moldings. I cut out the kink and used a 3/8 PVC splice I made to correct this. Unbelievable they assembled it like this.
I saw this on YouTube. A guy named Nestor did it so I give him all the credit. I had water on the floorboard behind my driver’s seat in my 2014 Altima. Two mechanics tried blowing out the lines with compressed air, but apparently neither one of them bothered to test whether the drains were actually clear. Speed Test
I bought a $5 bottle of two-part drain cleaner and a turkey baster. I had about 3 feet of 3/8” (?) hose that fit snugly on the tip of the turkey baster. I sucked up the first liquid and put a dose at each corner, using the tubing to get way back to the rear drain holes. I rinsed out the tubing then did the same with the second liquid. I waited about 45 minutes (directions say 1 hour) and poured a little really hot water into each track. Voila! Water drained from all four corners. Never disassembled any part of the car.
Most sunroof clogs are a combination of tree sap and mud, so bug-splat remover usually works well and won't take the paint off the inside of your fenderwells.
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