[dubs86]

Long time lurker first time poster. I’ve seen a lot of posts regarding pooling water in the footwells and water stains in the headliners related to the front sunroof drains clogging, but I’m trying to find out if there are drains in the rear of the sunroof. Went out to my 2018 XC90 after a recent deluge and found water dripping out of the 3rd row seat belts on the passenger side, and 2-3 inches of water standing in the plastic tray above the fuse box. Took the tray out to find another 1-2 inches of standing water in the fuse box compartment (because who doesn’t love spicing things up with a little water/electricity combo). My dealership can’t get me in for 2+ weeks but thinks it’s a sunroof drain issue and suggested I tarp the car if it rains again until they can take me. As much fun as that would be, I kind of need to drive even if it rains.

I found a truly excellent post from @wat5 (Rear sunroof glass cracked. Possible DIY replacement?) on removing the rear panel of the panoramic sunroof, but before I do - are there even drains in there, or am I barking up the wrong tree?

FWIW - regarding the electrical system, I’ve been driving for a bit both while there was water in there (before discovery) and since (after wet vac-ing out the standing water) and somehow miraculously all seems well. I don’t think the water level got high enough to actually reach the box…

Thanks!!

 

[volvogod]

There are 2 rear SR drains located on each side rear of the car. Here are pics of the drains. The Red and Brown plastic lines. The rubber elbow at the lower outlet end can fill with mud and block the flow of drain water. It backs up the hose and spills out at the top of the SR tub. Remove and check each rear drain hose end for being open or clean it out if blockage. If the rubber elbow end has the rubber tip almost closed or touching, cut the rubber end off to open the exit drain hole. Dust/dirt gets in the SR tray even if you never open it. The drain water flushes the dirt to the end of the rubber elbow. Over time this mud will dry, start to build up and eventually restrict and block the water drain exit.
330 and 331 JPG, this is the right rear corner, inspect the drain hose for being pinched in the connector. If yes, remove it from the connector. try to squeeze it round again. leave it out of the connector. With the rear drain hoses cleaned and open, drive the car so that the front is aimed uphill a lot. Open the roof glass, pour water into the SR tray, each side, and look for water exiting behind each rear tire area.

 

[dubs86]

There are 2 rear SR drains located on each side rear of the car. Here are pics of the drains. The Red and Brown plastic lines. The rubber elbow at the lower outlet end can fill with mud and block the flow of drain water. It backs up the hose and spills out at the top of the SR tub. Remove and check each rear drain hose end for being open or clean it out if blockage. If the rubber elbow end has the rubber tip almost closed or touching, cut the rubber end off to open the exit drain hole. Dust/dirt gets in the SR tray even if you never open it. The drain water flushes the dirt to the end of the rubber elbow. Over time this mud will dry, start to build up and eventually restrict and block the water drain exit.
330 and 331 JPG, this is the right rear corner, inspect the drain hose for being pinched in the connector. If yes, remove it from the connector. try to squeeze it round again. leave it out of the connector. With the rear drain hoses cleaned and open, drive the car so that the front is aimed uphill a lot. Open the roof glass, pour water into the SR tray, each side, and look for water exiting behind each rear tire area.

This is truly excellent, thank you so much!! I’ll be giving this a shot this weekend and will report back.

 

[dubs86]

Got this squared away this afternoon. It was definitely the SR drains, but not the hoses: the drains themselves were completely blocked at the top. After removing the sunroof like @wat5 had talked about in their sunroof replacement thread, I was able to put eyes on both drains.

I didn’t want to push all that grime down onto the drain so I used a can of compressed air (like from a computer cleaner) up the drain line to clear the blockage at the top of the drain, which worked like a charm!

It’s all back together and about to rain, so I guess we’ll see if I sealed everything well.

I definitely have the shrinking seal that’s the subject of this TJ, which is I’m guessing how all that dirt and leaves and twigs got in there, especially since there’s a tree right above the driveway: https://static.nhtsa.gov/odi/tsbs/2022/MC-10212893-9999.pdf

Will be getting that rectified soonest so I don’t have to do this again…

 

[theclutch]

View attachment 158927

I'm not sure what I'm looking at here. The area you circled in red looks like a crack vs a drain area. Per chance, do you have a pic of it clean or what it's supposed to look like?

Lastly, you mentioned you had to remove the sunroof to access this. Do you think it's possible to access this with a borescope so that we can check if ours is blocked or not?

Thanks in advance!

 

[dubs86]

do you have a pic of it clean or what it's supposed to look like

The area circled in red actually is the drain, but it’s so covered with leaves and twigs, it’s completely obscured. The second picture in my post above is the area after I cleaned it out, but despite several attempts, I couldn’t get my phone to actually focus on the drain area. Here it is again, circled in red, to better highlight the drain in the shadows:

I was able to get a much better picture of the drain on the other side, which, while far from clean, was unobstructed, and may help in finding the drain in the above photo:

If you have the weather strip gap issue I have, you might be able to feed a scope in through there. With the sunroof open, you might even be able to feed a scope along the outermost channel under the length of the rear glass (look for the drains on the front, outside of the pop-up wind deflector; the rear drains are in that same channel). You might even be able to scope it from going up the end of the drain line (you can access the passenger-side drain hose from the fuse box area - look for the brown hose going into a black connector in the side of the body of the car), though the diameter of the hose and any pinching from the mounting clips might be a limiting factor.

For what it’s worth - removing the sunroof wasn’t difficult, as long as you have a T20 torx driver. The hardest part was putting it back in flush with the roof - definitely needed a second person to help with that so you know when to snug the screws back down.

 

[volvogod]

You did an awesome job locating the blockage, taking pictures and opening up the drain area. Good chance that the dealership would have taken a lot more time to eventually finding this. This blockage would not have been covered by any CPO warranty if you have any warranty coverage. Hopefully other SPA XC90 owners will see this, check, test and clean out their SR drains and not wait until water is pouring inside the car.

 

[theclutch]

The area circled in red actually is the drain, but it’s so covered with leaves and twigs, it’s completely obscured. The second picture in my post above is the area after I cleaned it out, but despite several attempts, I couldn’t get my phone to actually focus on the drain area. ...

OMG, yours was completely blocked such that the round cross section wasn't even visible! THANKS for the detail and pics!!!

 

[cmyachtie]

some additional advice for ppl freaking about this drain getting clogged up, if you car is generally garaged, don’t fret as chances of drains clogging is rare, it’s mostly from cars being parked in the elements outside that get clogged up sooner.

 

[Ultrarunner511]

some additional advice for ppl freaking about this drain getting clogged up, if you car is generally garaged, don’t fret as chances of drains clogging is rare, it’s mostly from cars being parked in the elements outside that get clogged up sooner.

The problem I encountered with my former new 2020 was... the dealer parked it long term in their lot. The lot had numerous large trees that shed essentially year round. Never had confirmation if the drains were clogged or pinched. But it landed on the lot in August and I bought it new in May. That's a lot of undocumented time.

Sent from my SM-G781V using Tapatalk

 

[Tank010]

The area circled in red actually is the drain, but it’s so covered with leaves and twigs, it’s completely obscured. The second picture in my post above is the area after I cleaned it out, but despite several attempts, I couldn’t get my phone to actually focus on the drain area. Here it is again, circled in red, to better highlight the drain in the shadows:

View attachment 159077

I was able to get a much better picture of the drain on the other side, which, while far from clean, was unobstructed, and may help in finding the drain in the above photo:

View attachment 159078

If you have the weather strip gap issue I have, you might be able to feed a scope in through there. With the sunroof open, you might even be able to feed a scope along the outermost channel under the length of the rear glass (look for the drains on the front, outside of the pop-up wind deflector; the rear drains are in that same channel). You might even be able to scope it from going up the end of the drain line (you can access the passenger-side drain hose from the fuse box area - look for the brown hose going into a black connector in the side of the body of the car), though the diameter of the hose and any pinching from the mounting clips might be a limiting factor.

For what it’s worth - removing the sunroof wasn’t difficult, as long as you have a T20 torx driver. The hardest part was putting it back in flush with the roof - definitely needed a second person to help with that so you know when to snug the screws back down.

Can you clean it without removing the sunroof? I just want to check it periodically and keep it clean.

 

[byrdyb]

Why wouldn't this issue be covered by warranty? Seems to me to be a design flaw. And no where in the manual does it state that checking for pano roof blockages should be part of an owner's regular maintenance. Not one mention of it.