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DIY: How to clear the convertible's drain holes

165K views 59 replies 46 participants last post by  Aleksvi123 
#1 ·
I've searched long and hard and I've not found a "how to" for clearing the drain holes at the front of the convertible cover well. So here goes...

Tools required (Image01)...

1. 1/4" ratchet drive
2. 3" extension (1/4")
3. 6" extension (1/4")
4. 10mm socket (1/4")
5. 8mm socket (1/4")
6. 7mm socket (1/4")
7. 3/8" ratchet drive
8. 3" extension (3/8")
9. 6" extension (3/8")
10. 13mm socket (3/8") - deep socket optional
11. 5mm hexagon head socket (Allen head) (3/8")
12. Snipe-nosed pliers
13. Forked upholstery tool
14. 13mm ratchet ring spanner
15. 10mm ring spanner (ratchet optional)
16. Stanley knife
17. A ground toothbrush to retrim the car without scratching the paintwork
18. Some wood to hold the roof and roof compartment
19. Foam to support front of roof
20. Compressed air supply and hose
21. Water hose
22. Towels

Stage 1 - Preparation

1. Fully lower the roof.
2. Remove the rear seat and store it safely. [Tools 1, 2 & 4]
3. Remove the middle side trim panel (part with armrests) - both sides. Thde two bolts are in each armrest and need to be removed. [Tools 1, 2 & 5] Any trim clips should be removed using tool 13 if possible (see Image02 B). Remove any clips from the car and attach to the trim before refitting. Disconnect the tweeter cable (see Image02 C).
4. Disconnect the slide cover return spring (see Image03) - both sides [Tool 12].
5. Remove the small upholstery rivet (see Image04) - both sides [Tool 13].
6. Remove the upper side panel - both sides. Three bolts (see Image02 A) to be removed [Tools 1,2 & 6].
7. Remove the lower side panel -both sides. Slide the trim upwards to remove. Again remove any trim clips from the car and fit them to the trim. [Tool 13]

Stage 2 - Lifting the roof

1. Operate the roof so the rear of the roof and the opening comparment are as high as possible.
2. Chock open the roof and the compartment (see Image05 & Image06)
3. Using Tool 15 disconnect the hard top attachment and move it aside (see Image07 A) - both sides.
4. Using Tools 7, 8 & 11 disconnect the cover lock (see Image 07 B) - both sides. Be careful not to drop the Allen headed bolts. Note any witness marks for refitting.
5. Release the cables from the catches (see Image08) to allow the lock to be moved aside.
6. Loosen the nuts holding the roof onto the bracket (Image09, Image10 & Image11) - both sides. [Tools 7, 9,10 & 14] Note witness marks for refitting.
7. Support the front of the roof using foam or such like.
8. With the aid of an assistant remove the nuts.
9. Manoeuvre the roof so you can see the drain hole (see Image12).

Stage 3 - Clearing the blockage

1. Attempt to clear the blockage using a hose and compressed air.
2. Test with a water hose.
3. Use the towel to soak up any spillages. Micro-fibre towels are ideal.
4. Use the knife to cut through the sound-proofing under the seats as water is bound to collect here.
5. If you need more access, you can remove the roof bracket. You will need a 13mm ratchet ring spanner to do this [Tool 14].

Stage 3a - Removing the roof bracket

1. Behind the bulkhead (Image11) you should be able to see a 13mm nut. Loosen this nut. Do not remove it yet (or you may never see it again!) [14]
2. Remove the nuts shown in Image13 and Image14. [Tool 7 & 10]
3. Remove the nut attached to the stud next to the drain hole in Image15. You will need to use Tool 14 to do this.
4. Remove the loosened nut behind the bulkhead. You will be able to use the play in the bracket to get your fingers in the gap to retrieve the nut. [Tool 14]
5. You will have much more access to the drain hole and should be able to clear any blockages.
 

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#3 ·
This was great, the holes in my convertible were clogged bad and water was seeping into the trunk. I was looking at around $1000 to have the dealer do the work. My son and I followed your instructions and it worked perfectly. It took us a couple of hours, not bad at all.

thanks.
 
#4 ·
water in boot

i have just followed these instructions and it turns out it is a very easy fix and would not have any concerns doing it again took about two hours from start to finish and that is putting all carpets back in the boot as they were all soaked eptied about 6 litres out the spare well and battery box definately worth having ago yourself dealers will charge a small fortune to do definatley a problem from BMW something you would not expect to happen on a expensive car:thumbsup:
 
#5 · (Edited)
Do you need to remove the Interior Bits & Pieces?

Thanks for the great write-up.

My car is suffering from this as well -- and got a minimum estimate of $1250 from the local BMW dealer to unplug these holes. (10 hours @ $125 / hour + 4 hours to dry out the rugs + another 1 hour + $460 to replace a slightly torn gasket -- Yikes! $2000+

Soooo ... I'm now on to Plan B.

I haven't yet looked closely at my car, but do you really need to remove all of the interior bits and pieces to do this? Are these items in the way of getting at the weep holes?

Thanks for your help in advance....
 
#6 · (Edited)
Worked like a charm ...

Followed the procedure as noted -- and it worked great.

Though I had to buy a few tools I didn't have, it was well worth the investment -- saved well over $1000.

All totaled - buying the necessary tools excepted - it took me ~ 3 hours - counting the repeat disassembly after I dropped a couple of screws that attach the deck latch down into the cavity during reassembly -- grr...

You definitely need two people for a couple of steps -- but otherwise pretty straight forward. I should also mention that a fairly large TORX wrench is needed to unbolt one of the rear seat belts to remove the rear seat.

Thanks for the writeup.

My local BMW dealer should be ashamed of themselves. Seeking to charge 10 hours of labor to do this task is ridiculous....

KPT

(ps... the weep holes are draining well -- and the trunk and passenger compartment are bone dry after this effort -- sure beats the 10" of standing water I had in the trunk....)
 
#9 ·
You definitely need two people for a couple of steps -- but otherwise pretty straight forward. I should also mention that a fairly large TORX wrench is needed to unbolt one of the rear seat belts to remove the rear seat.

i slid the seat belts around the seats after i unattached the seats so that i didn't have to take the seat belts screws off, if that helps for the future. :)
 
#8 ·
did this 4 days ago....great DIY, but i ddi have to remove my seats cuz the foam under the seats got wet. i do have one question for those who did it though......

my rear passenger footwell still has water going into it from somewhere. i cleared the drain plug and tested it, but i washed the car 1 day after install and more water showed up. is there any other place (i.e. the passenger door) that would make the water drain into there?????? im baffled.
 
#10 ·
...my rear passenger footwell still has water going into it from somewhere. i cleared the drain plug and tested it, but i washed the car 1 day after install and more water showed up. is there any other place (i.e. the passenger door) that would make the water drain into there?????? im baffled.
Yes, take the door panel off and check that the foam liner (I think it is also called a vapor barrier) is in place. Have someone pour water down the outside of the window glass, simulating a heavy rain, and make sure nothing drips down the inside of the door from the barrier. If it does then you should be able to trace it from there. Let us know what you find out!
 
#12 ·
Another bump - Just wanted to say THANK-YOU! for this. It wasn't really too hard at all! Probably the most mechanically inclined thing I've ever done, and it wasn't too bad at all. Coming from someone who has very limited mechanical experience.

The only thing I scratched my head at was...

"3. Using Tool 15 disconnect the hard top attachment and move it aside (see Image07 A) - both sides."

Looking at the pictures, and my car side by side - I didn't know what to unbolt. Couldn't see any bolts in the picture, or on my car for this. In the end I decided maybe I don't have any sort of hard top attachment (Thought you bought those when you bought a hard top?) and skipped this step. Had no issue beyond that.

Tested by dumping a good liter of water over the hole on each side - No backup,plugs, or anything - It all drained out under the car after blowing the lines out with an air compressor.

I'm really happy with this, thanks a million!
 
#14 ·
Brilliant thread! I've just spent an hour cleaning out a couple of gallons of rain water from my spare wheel well and roof compartment, so now I know what I am facing.

One question, maybe a bit silly, but... where do these drain holes lead to? And more specifially, what does prevent us from putting the air hose at the bottom end of these drain holes and blow all crud out the other direction, leaving the roof structure where it is?

Or would that be over-simplifying things a bit??

Thanks!

Hans
 
#16 · (Edited)
Okay, in response to my own postings:

1: the drainholes end up in some nondescript slots at the bottom. Not the place to pick them open. So an approach from the top IS needed.

2: The side panels need to come off. The Bottom side panel doesn't, but the rest is required.

Did the job in 2 hours flat today. Got the roof OFF myself, but putting it back on required the help of a buddy.

Three comments:

1: taking the top side covers off is a bit tricky. One is inclined to slide them forward. DON'T. You'll break off some plastic lip. The key is to LIFT them off. This requires pulling of about 2" of the U-shaped edge cover at the very aft part of the panel. A no-brainer.

2: I found that I needed to unplug the wires leading to the cover locking mechanism, as they interfered with lifting the roof mechanism off. Easy enough.

3: The sound dampening material under the back seat can be lifted, so it doesn't require cutting in order to get the water from underneath out. DON'T cut - you'll risk cutting through the paint and therefore risk long term rust problems there.

Thanks for this excellent DIY!! :clap:

Hans
 
#19 ·
I got same problem 2 years ago, I have another solution "Bottom-up".

I did it when my car jacked up at a wheel shop.
1. open top in half way
2. pour some water at upper drain hole
3. find where the water drain out, it is around the rear wheel housing.
4. use compress air gun to blow the hose from bottom. clogged dirt will be blowed from upper drain hole.

ps. if you car is very low near ground, maybe you need to jack up your car firstly.

 
#21 ·
Alternate solution requiring NO WORK!

I noticed these hard to find drain holes cloking up...if it rains long enough or it sloshes around while your driving this water will accumulate in trunk.

OK, here is what I found out....it has NEVER FAILDED TO WORK for me!!!

Pore a 1/2 cup of favorite DRAINO drain clog remover into the areas that contain the water...the area under to convertible top lift mechanisim.

In minutes you should see water dripping rapidly from underneath the door area.

PS, I actually fill those same areas will water after they empty to clear out the remaining DRAINO....
 
#24 · (Edited)
Drano Clears BMW Convertible Drains --No More Water in Spare Tire Well!

1. Get the strongest liquid drain cleaner you can find.
2. Open convertible top part way, prop open if needed, so you have clear access to the main hinge assemblies
3. put newspaper along edge of running boards, weight them down --this helps you see when drains clear, and protects surface from drain cleaner
4. Use strong vac, with narrow tip to remove all debris you can while it's dry, both sides of both hinge assemblies --remember, you're clearing out a horizontal space, through under the hinge (awful design!)
5. same idea, but using water With vac tip deep as possible on inside edge of hinge assembly, sucking, spray strongest hose-nozzle stream into deepest spot on outside edge
6. Reverse positions of water stream and vac tip, spray-and-suck again
(Doing 5 and 6 on both hinge assemblies dislodges/vacs out a good bit of the debris --but probably not the real clog. Check Newspapers you laid out for drip marks.)
7. pour 1/2 cup of the drain cleaner into each hinge area and go for a run or something --I let mine sit for about an hour
8. replace the newspapers, consider putting glass cups under ID'd drip points
9. vaccuum out both sides of both hinges to get any remaining drain cleaner out before step 10.
10. WITH SAFETY GOGGLES and old clothes on, repeat steps 5 and 6
11. repeat step 7, look immediately to see if it flows right through or not. If so, wait a few minutes, remove catch cups, rinse once more --you're done. If no, have another run, repeat 9 and 10 --should flow right through.
 
#29 ·
I did this job yesterday and I really appreciate the pics and tutorial. I thought I would post my experience to further help the next person who does this job.

1. I tried the drain cleaner method first.( liquid plumber gel) One side drained a little but later stopped up again as I was flushing it. The other side did nothing.

2.I tried both air pressure and water jet through the drain holes (when I finally found them) with no success. I also tried running a wire up from the bottom and never got very far. ( I'm posting a picture of the holes so you can find them but that method is not recommended.)

3. I finally decided to bite the bullet and clear the holes from the top and it really wasn't as hard as I imagined after reading this thread. I did the job by myself in about an hour and learned a few tricks. Here's the abridged version:
a) remove 2 armrest screws on one side
b)remove center panel behind it
c) 3 trim screws and rubber unhooked from rivet takes off the top panel to get to the hinge.
d) loosen the slotted hinge bolt behind the top panel.
e) remove 3 bolts on the back side of the hinge and leave its mounting plate fastened.
f) lift hinge about 2 inches and slide a block of wood under it to hold it up. I used a 2X2.
g) clear the hole with wire and hose stream and then reassemble.
h) repeat on side 2
I didn't remove the seat or unplug any wires and by doing it one side at a time it becomes a one man job. Also when you get the drains really cleared they make a whirlpool and sucking sound like your tub. Don't settle for less.
Good Luck!
 

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#37 ·
Guys, I have to tell you this solution works the best and in the least amount of time. It took me 1 hour to do clear the drains on both sides...and what was funny was the fact that once the drains were cleared, they each made the whirl pool sucking sound.

Dont waste your time pulling the seat and disconnecting wires, not one wire was disconnected in this way of clearing the drains. I did pour boiling water down each hole after I cleared the blockage and now the car drains perfectly.

No more water in the trunk!!!:thumbsup:
 
#30 · (Edited)
excellent write up. I didn't even know this problem existed on the convertibles until seeing this post. I went outside and tested both drains with water. Passenger side was flowing very nicely, but driver's side was draining very slowly and holding some water. I tried flushing it down with some hot water but no go so I followed this DIY to lift off the left side of the convertible frame. Wasn't hard at all. Getting the frame off the base was a bit of a bear because you have to put pressure on the front of the top so it balances itself a bit. Sure enough, I got to the hole and it was plugged up. While I was in there, discovered the front-facing base nut was completely loose and about to fall off! I am assuming from a previous repair job by the dealer.

It's nice to be able to leave the hydraulics connected and just move the base out of the way. Took my pipe cleaner set from harbor freight and went to town on the drain. Flushed it a few times and it is now sucking the water down very quickly.. even making sucking sounds like the other side. Thank you!
 
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