Cascada rear drain(s) clogged (water sloshing sound)

Oliver H

New member
2
2
1
Buick Ownership
2016 Cascada
How to clean out the clogged rain water drains located in the right-rear and left-wheel wells.

1) remove left rear wheel.
2) partially remove wheel well liner (rear fender liner).
3) locate 1/4" drain hole, and clean out with a pipe cleaner or small screw driver.
(Rain Water trapped inside )

Repeat the same process for right side.

SYMPTOMS:
- hear water sloshing around when going over speed bumps or driving on bumpy roads at slower speeds.

- wet carpet behind driver or passenger seat floor (rear carpet).

- rain water dripping near rear wheel well....for serveral hours, after rain has stopped.

There are (2) rain water drains that get clogged up that need to be cleaned out occasionally. In NC, I get the long pine needles which get inside a hollow body area......that rain water get inside and that has a drain to let the rain water out.

See:
PIMPmyCASCADA
there are pictures at this link which show the steps.

There is no mention about this in the Cascada owner's manual.
You should not hear any water sloshing sounds....... inside the Cascada passenger cabin, ever.
 

G-583090

How to clean out the clogged rain water drains located in the right-rear and left-wheel wells.

1) remove left rear wheel.
2) partially remove wheel well liner (rear fender liner).
3) locate 1/4" drain hole, and clean out with a pipe cleaner or small screw driver.
(Rain Water trapped inside )

Repeat the same process for right side.

SYMPTOMS:
- hear water sloshing around when going over speed bumps or driving on bumpy roads at slower speeds.

- wet carpet behind driver or passenger seat floor (rear carpet).

- rain water dripping near rear wheel well....for serveral hours, after rain has stopped.

There are (2) rain water drains that get clogged up that need to be cleaned out occasionally. In NC, I get the long pine needles which get inside a hollow body area......that rain water get inside and that has a drain to let the rain water out.

See:
PIMPmyCASCADA
there are pictures at this link which show the steps.

There is no mention about this in the Cascada owner's manual.
You should not hear any water sloshing sounds....... inside the Cascada passenger cabin, ever.
Thank you sooo much! Definitely going to try this, had a lot of rain and it leaked 😪
 

Rcoyte

New member
1
0
1
Buick Ownership
Cascada
How to clean out the clogged rain water drains located in the right-rear and left-wheel wells.

1) remove left rear wheel.
2) partially remove wheel well liner (rear fender liner).
3) locate 1/4" drain hole, and clean out with a pipe cleaner or small screw driver.
(Rain Water trapped inside )

Repeat the same process for right side.

SYMPTOMS:
- hear water sloshing around when going over speed bumps or driving on bumpy roads at slower speeds.

- wet carpet behind driver or passenger seat floor (rear carpet).

- rain water dripping near rear wheel well....for serveral hours, after rain has stopped.

There are (2) rain water drains that get clogged up that need to be cleaned out occasionally. In NC, I get the long pine needles which get inside a hollow body area......that rain water get inside and that has a drain to let the rain water out.

See:
PIMPmyCASCADA
there are pictures at this link which show the steps.

There is no mention about this in the Cascada owner's manual.
You should not hear any water sloshing sounds....... inside the Cascada passenger cabin, ever.
So this just happened to our 2016 Cascada. We didn't know about this. we bought an extended warranty with our car. We turned our car in because the passenger rear window was operating on its own. This problem was discovered. We were told this is about 3k in damages and not covered by the warranty. The dealer said we have to replace the wire harnesses, all the seats need to come out for this, carpet too. Plus replace the harnesses and pulleys for the top. Dealer said this is not covered by the warranty because it is in the owners manual.

Thoughts?
______________________________
 

2007LucerneCXL

Full Member
9,764
3,438
113
Illinois
Buick Ownership
2007 Lucerne CXL. and 1995 Lesabre currently, past 1973 Riviera, 1968 Riviera
Oliver H - Joined Aug 30, 2019 - Last seen Aug 31, 2019, doubtful a reply will be coming.
 

ImperialPint

New member
7
0
1
Buick Ownership
Cascada
So this just happened to our 2016 Cascada. We didn't know about this. we bought an extended warranty with our car. We turned our car in because the passenger rear window was operating on its own. This problem was discovered. We were told this is about 3k in damages and not covered by the warranty. The dealer said we have to replace the wire harnesses, all the seats need to come out for this, carpet too. Plus replace the harnesses and pulleys for the top. Dealer said this is not covered by the warranty because it is in the owners manual.

Thoughts?
Oh man...this afternoon (April 20, 2021) we got a call from our daughter who has a 2016 Cascada in Florida. She reported lots of water inside and then wacky dashboard lights and remote lock not working. So the info here on the forum has been very helpful, at least we know how to fix the water problem! The electronics though...has me worried. Sounds similar to Rcoyte's issues. Is this true...that if it's in the owner's manual then tough luck? Damn.
 

2007LucerneCXL

Full Member
9,764
3,438
113
Illinois
Buick Ownership
2007 Lucerne CXL. and 1995 Lesabre currently, past 1973 Riviera, 1968 Riviera
No confirmation, so you may need to read the manual to see if is stated in it.
 

ImperialPint

New member
7
0
1
Buick Ownership
Cascada
No confirmation, so you may need to read the manual to see if is stated in it.
I have completed my evening's homework: reviewing the 381 page manual for the 2016 Buick Cascada. I see nothing in there about drain holes. In my assessment, this issue is NOT addressed in the owner's manual.
______________________________
 

2007LucerneCXL

Full Member
9,764
3,438
113
Illinois
Buick Ownership
2007 Lucerne CXL. and 1995 Lesabre currently, past 1973 Riviera, 1968 Riviera
Post #1 said it wasn't, Rcoyte who was a one and done post was told by a dealer and your post says it isn't in the owners manual.

Unless someone can get GM to cover costs if needed or still has a warranty it's just a FYI for owners to mindful of.
 

ImperialPint

New member
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0
1
Buick Ownership
Cascada
Bringing closure to the story of the water logged Cascada with subsequent electrical wonkiness. In the end, once the car was dried out, the electrical problems went away. The shop (dealer) did not end up replacing any parts; but did have to pull the interior out (seats, carpet) to dry it all out. That bill was $1200...which was covered by my insurance. They also recommended a new battery, which I got. As soon as the car was ready, my daughter and I drove it 1200 miles in 2 days, from Orlando FL to Ithaca NY, with no problems. Unfortunately, nobody at the shop discovered the root cause of the flooding nor the wonky electrical behavior. They did report that one of those drains that exits the wheel well was clogged...but frankly the messaging was unclear and in the end I have no good grasp on what to check on going forward. No one was able to connect the dots between standing water in the vehicle and the electrical problems. It seemed like they wanted to pin the electrical problems on the VCM (located under the hood) and said that maybe it was getting dripped on by the air conditioner...but never really proved that was the case. The shop was clearly not familiar with the vehicle. The service manager told me that the wiring diagram was "complicated" (!). It was disappointing for me to have us doing the online research and bringing the official Buick service bulletin to the attention of them (the GMC dealer service shop) to address the drain/flooding. So, moving forward with fingers crossed and more diligent checking the carpets for signs of moisture. And keeping it under cover as much as possible.
 

ImperialPint

New member
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0
1
Buick Ownership
Cascada
Took it through the car wash for the first time since the May incident. Got home, and water dripping from right rear well...I'm thinking that is good as per discussions above. But no water dripping from left rear well....so....might dive in myself tomorrow with removing the wheel and partially removing the wheel well liner and seeing what is up.
 

Vector

New member
14
3
3
Buick Ownership
2016 Cascada
Oh man...this afternoon (April 20, 2021) we got a call from our daughter who has a 2016 Cascada in Florida. She reported lots of water inside and then wacky dashboard lights and remote lock not working. So the info here on the forum has been very helpful, at least we know how to fix the water problem! The electronics though...has me worried. Sounds similar to Rcoyte's issues. Is this true...that if it's in the owner's manual then tough luck? Damn.

If this happens to anyone, you need to fix the problem first by clearing the clog, then removing the rubber flap/s to prevent it from happening again.

After that, you need to dry our the interior carpet/seats of as much moisture as possible. I used towels to absorb as much as possible, then used my wet/dry vac to suck out more water/moisture out of the carpet and padding. Once I got as much out as it could, I opened up the top and let the sun bake the interior for hours. Then when I reclosed the roof, I put the A/C on high, lowest temp and recirculated interior air for at least an hour.
Then I put in a damp rid in, along with a dehumidifier from my gun safe over night;


Then repeated the process of having the sun blast it all day again. After recharging my dehumidifier, and placing it in again overnight, all the moisture was gone. I never had any electrical issues, likely because I didn't allow moisture to permeate the interior for too long.
______________________________
 

macmancapecod

New member
3
0
1
Buick Ownership
Cascada
How to clean out the clogged rain water drains located in the right-rear and left-wheel wells.

1) remove left rear wheel.
2) partially remove wheel well liner (rear fender liner).
3) locate 1/4" drain hole, and clean out with a pipe cleaner or small screw driver.
(Rain Water trapped inside )

Repeat the same process for right side.

SYMPTOMS:
- hear water sloshing around when going over speed bumps or driving on bumpy roads at slower speeds.

- wet carpet behind driver or passenger seat floor (rear carpet).

- rain water dripping near rear wheel well....for serveral hours, after rain has stopped.

There are (2) rain water drains that get clogged up that need to be cleaned out occasionally. In NC, I get the long pine needles which get inside a hollow body area......that rain water get inside and that has a drain to let the rain water out.

See:
PIMPmyCASCADA
there are pictures at this link which show the steps.

There is no mention about this in the Cascada owner's manual.
You should not hear any water sloshing sounds....... inside the Cascada passenger cabin, ever…
 
Last edited:

macmancapecod

New member
3
0
1
Buick Ownership
Cascada
How to clean out the clogged rain water drains located in the right-rear and left-wheel wells.

1) remove left rear wheel.
2) partially remove wheel well liner (rear fender liner).
3) locate 1/4" drain hole, and clean out with a pipe cleaner or small screw driver.
(Rain Water trapped inside )

Repeat the same process for right side.

SYMPTOMS:
- hear water sloshing around when going over speed bumps or driving on bumpy roads at slower speeds.

- wet carpet behind driver or passenger seat floor (rear carpet).

- rain water dripping near rear wheel well....for serveral hours, after rain has stopped.

There are (2) rain water drains that get clogged up that need to be cleaned out occasionally. In NC, I get the long pine needles which get inside a hollow body area......that rain water get inside and that has a drain to let the rain water out.

See:
PIMPmyCASCADA
there are pictures at this link which show the steps.

There is no mention about this in the Cascada owner's manual.
You should not hear any water sloshing sounds....... inside the Cascada passenger cabin, ever.
This problem keeps happening in our 2017 Cascada. Had it back to our Buick dealer twice and now it’s going back a third time. They know all about it, but don’t know how to keep it from happening again.
This me, it’s a design flaw, one that GM needs to cover! I’ve owned a lot of cars but never had such a problem.
Going to reach out to GM about this recurrent issue. Will let you know if I get anywhere.
Anyone else with this issue, please post here. Thanks!
Love the car! But this water issue is not acceptable!
======UPDATE FROM BUICK NEXT DAY ======
Hi there, Dave. We're certainly sorry to hear about your recurring water concern. Please know that our dealerships are in the best position to assist in matters like these. If you would like us to reach out to your dealer to gain some insight on this matter, we would be happy to do so. However, if they were unable to find a resolution, we are unable to guarantee a different outcome. Please let us know how you wish for us to proceed. Deanna L.
BOTTOM LINE; " You're on your own, buddy!"
Thanks, GM.
 
Last edited:

Vector

New member
14
3
3
Buick Ownership
2016 Cascada
This problem keeps happening in our 2017 Cascada. Had it back to our Buick dealer twice and now it’s going back a third time. They know all about it, but don’t know how to keep it from happening again.
This me, it’s a design flaw, one that GM needs to cover! I’ve owned a lot of cars but never had such a problem.
Going to reach out to GM about this recurrent issue. Will let you know if I get anywhere.
Anyone else with this issue, please post here. Thanks!
Love the car! But this water issue is not acceptable!
======UPDATE FROM BUICK NEXT DAY ======
Hi there, Dave. We're certainly sorry to hear about your recurring water concern. Please know that our dealerships are in the best position to assist in matters like these. If you would like us to reach out to your dealer to gain some insight on this matter, we would be happy to do so. However, if they were unable to find a resolution, we are unable to guarantee a different outcome. Please let us know how you wish for us to proceed. Deanna L.
BOTTOM LINE; " You're on your own, buddy!"
Thanks, GM.

I don't know if you have read my earlier post, but the way to resolve this problem for good, is to remove the flap that covers the holes. It can be done with a pen knife as the flaps are pliable rubber like material. Otherwise they will fill with debris and the flap acts like a barrier to create a clog.
I don't know what the idea of the flaps purpose is, but if I had to venture a guess, it might be to prevent insects or air into the tubes.

Needless to say clogs of drain tubes can occur in any car, especially ones with sun/moon roofs where you typically have 4 drains. Another thing you can do to help is not park under trees with a lot of leaves, berries or small twigs that will work their way into the drain-lines in a heavy rain.
______________________________
 

macmancapecod

New member
3
0
1
Buick Ownership
Cascada
Fabulous! A million thank you's Vector! I am going to tell my dealer and GM about this. Sounds like an easy fix but will have the Dealer do it to be on the safe side. Thanks again!!!
 

K Rae

New member
3
0
1
Buick Ownership
2016 Cascada
So this just happened to our 2016 Cascada. We didn't know about this. we bought an extended warranty with our car. We turned our car in because the passenger rear window was operating on its own. This problem was discovered. We were told this is about 3k in damages and not covered by the warranty. The dealer said we have to replace the wire harnesses, all the seats need to come out for this, carpet too. Plus replace the harnesses and pulleys for the top. Dealer said this is not covered by the warranty because it is in the owners manual.

Thoughts?
I have a 2016 & the rear passenger window was doing the same!!
But my Buick dealer only charged $250 for a motor of some kind, fix the clogged drain & the labor

The window was clogging & they wanted to rip out carpet for $1000
I didn't do this- bought a can of mold killer at Wal- Mart & sprayed the heck out of it
Having thoughts now reading through this about cleaning those drains more- I really love that car, but don't want to start pouring $$ in
 
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TennisSlave

New member
1
0
0
Buick Ownership
2016 Casada convertable
Fabulous! A million thank you's Vector! I am going to tell my dealer and GM about this. Sounds like an easy fix but will have the Dealer do it to be on the safe side. Thanks again!!!
Good stuff, it only took me 30 minutes to take off both tires, remove the plugs permanently and clean out the tube and put every thing back on. Thanks!!!
 

Susan22

New member
1
0
0
Buick Ownership
Cascada
Helpful to hear about others' experience. My car's back at the dealership for the second time with this problem: water sloshing in the rear quarterpanels, water soaking into the carpet. It was covered under warranty the first time, but they want to charge $1000 now to unplug it, take out the rugs to dry, and replace. Agree with the person who said this is clearly a design flaw. I'm not going to authorize the repairs unless there's a more permanent solution. The dealer tech has so far just offered that they could drill a couple of additional holes. Helpful to know about the flap issue! Otherwise, they've advised me to put a cover on it when it rains. I haven't had a chance to have that conversation in person so I can see if they can keep a straight face while saying that is a good solution. If the flap issue can't solve this I will want to sell the car - not an acceptable problem.
 
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