BMW Z4 How to Clean The Convertible Drain Holes

Here is a video on how to access and clear the convertible top drain holes on an E85 BMW Z4. If the drains are clogged the convertible top motor will rust and fail. This preventative maintenance can save you several thousand dollars by avoiding a costly motor replacement. It is not a regular service item so you need to have the drains cleared regularly.

[@jmichaeltaylor2127]

I’ve had many problems with my Z4’s convertible top motor. BMW, in all of their design/engineering brilliance, located the convertible top hydraulic motor in a location that allows for water to pool and submerges the motor in water from rain or washing your car. Eventually, this motor is going to fail. It is not designed to be submerged. I relocated my top’s motor to the trunk of the car, thereby keeping the new motor dry. I also placed a spongy rubber mat under the motor to support the motor and protect it from vibration. Make sure you check the motor for hydraulic fluid. If it doesn’t have enough fluid, the performance of the top will suffer. This goes for the hydraulic lines. They must be in good condition. I have replaced all but the front locks of the convertible top. Guess those will go bad next! BMW is fully aware of these problems and have consistently refused to do any sort of recall, shop fix, or even give you a discount on the parts needed to fix their poor design. If you pay the dealership to do the work, have deep pockets lined with cash. It will cost you. This work can be done yourself. It is not that hard, but is time consuming. Having a friend to help you remove the convertible top will help, but others have been able to remove the top’s motor without completely removing the top. On US cars, the motor is behind the driver’s left shoulder, in between the driver’s compartment and the trunk compartment. Take your time and good luck!

[@migelprager1097]

@@rossandmusic DIFY ... and you know what that extra "F" means...

[@jafxdwg]

Thanks nman2563 ! I watched your video this morning and got ambitious to change over my winter tires for the summer set. After watching your detailed video I took the time to service the drains. Actually when I took out the plugs, I discovered they were in two pieces. A hard plastic base with a soft plastic valve. They came apart easily and I used the hard plastic part, taped to the end of my shop vac. This modified nozzle was a perfect fit.Your video is by far the best dealing with this service.

[@timvanackeren7184]

Thanks for this valuable info. Thought I would have to crawl under the car to get at the drains. This was very easy and was able to inspect the drain holes with a mirror to verify that they were clear prior to re-installing the rubber drain fittings on both sides. Obviously the plastic pocket with the motor in it is the one to worry about. My right side one was partially clogged, but I believe the top motor is in the left pocket so not too worried.

[@csquire3]

Good video, I'm an idiot and this helped me understand what I need to do. Thanks fella.

[@boandjill]

Thanks; this worked for me. I had a semi clogged drain plug on the bottom and the top was also mostly plugged. I tried to unplug the top drain, but couldn't seem to find the drain hole, so your method of vacuuming worked.

[@MervinIstace]

Well done video...easy to understand and helpful to all who own a BMW Z4 (E85)

[@nman2563]

+Mervin Istace Thanks Mervin!

[@herrboogie]

thx.. i read a lot of warnings about clogged drain holes and failing top motors, but no explanation about how to fix/avoid it

[@simonmakinson]

Brilliant description on how to do it. Thank you. Any more tips on the BMW E85 , please keep them coming, cheers...Simon.

[@pipandcol]

Chris Eubank doing BMW maintenance....................wow!!!

[@theninja250]

Question, why not remove the drain caps and keep them off so water cannot build up and possible fill top motor or trunk?

[@nman2563]

There is probably a good reason why they are there. I'm not going to find out the hard way.

[@FMFYou]

It's said that it's there to keep insects out. Actually a lot of Z4 owners removed it because they clog on aregular basis. They never had serious problems. Insects will still find a way in your car if they want to. Especially if your car is parked outside every night.

[@steveanderson1779]

@@FMFYou Thanks, i have removed mine

[@FMFYou]

@@steveanderson1779 I removed mine too a few weeks ago and I noticed that the driving noises got louder in the interior. Especially when it's raining. It isnt that annoying though.

[@minimeee04]

Completely pointless having the plugs in place as they serve no purpose.

[@WildCaterham1]

Great Video! Thanks So much for making this. I have been looking all over to see how this is done and couldn't find anything. This is exactly what I was looking for.

[@nman2563]

WildCaterham1 Glad to be of assistance!

[@dragutingotal5250]

Thank you for posting this video. Is it possible that you do another video with cleaning front drain wholes? The ones under the windshield.

[@jackbarrett7835]

Nice job. Thanks for the info

[@thehauke7981]

Thank you very much. Great video!

[@ua751920]

Excellent video thanks. from my experience the problem is not at the bottom end of the drain system but at the top end where the roof motor sits. the hole at the top end gets blocked and does not allow the water to drain down. on the other side I simply stuck a stick down and wriggled it about and the water came gushing down. you cannot do this on the roof motor side it's blocked. would be good to know how to get around this.

[@nman2563]

ua751920 Yes, the problem is with the drains getting clogged from the top. The hope is that the vacuum will be powerful enough to clear any dirt blocking the top as well. The only other option I know of to clean the motor side drain from the top is to completely remove the convertible top. I have thought of a way but need to test it first before confirming it works.

[@antonykeen123]

nman2563 hi - did you figure a way to clean the top of the motor side of the drain hole? Would be great to share with all here 👍

[@phaedrabacker2004]

Excellent. I needed that info.

[@PeteBurrows-sb7qv]

great video thanks

[@jonathanregis6136]

great thanks will give it a go now

[@michaeldenicola6725]

Thank you ithe video was very helpful

[@armando500]

It's not necessary to remove the wheel to do it. Thanks for sharing

[@nman2563]

armando500 Thanks. Yes, I mention that in the video.

[@lux512]

Is it located too in the right side for left hand cars? Thanx

[@prasheenbissessor2149]

Hi, Great Video. My Z4 M Roadster 3.2L 2007 is Right Hand Drive ... which side is the Motor ?

[@nin9919]

Thanks for the video. If you put the car up on a lift and can get under it, can you access the drain holes on both sides without taking off the wheels and the covers?

[@nman2563]

Yes, I believe you can

[@KhoaNguyen-xj6gk]

Yes you can. I recommend you buy a short rachet wrench for this job if you dont want to open the tire.

[@midnightpassion43]

Hello nman2563, I have a problem. I have a 2006 bmw 3 series e46 convertible. O.k. I notice there was water in my truck and in the battery compartment. would this plug you removed have anything to do with water getting in my truck where the spare tire is?? I need help with this if you or anyone else can help me. Thanks.

[@JHAldy10]

Do you know if the Z3 has a similar design? And what is the purpose of the plug? Why not remove it all together?

[@wlh227]

+Josh Aldy You will get unwanted road noise. I know because I removed mine.

[@wlh227]

+shorsheesure ceo it drains the water that seeps down into the area below where the top is secured to the body. For more infor see our clubs website. www.eastpazscca.org

[@midnightpassion43]

Hi Bill Harmon, will this plug being stopped up, causes water to get in the truck where the spare tire and battery compartment is???? I'm having this trouble. Pls help

[@hvdv780]

Unclogging the drain holes (E85) and removing the anti bugplugs (?) Can you put a flexible wire into the drain en push it upward in order to open possible clogs underway....And where will you see the upper end of the wire, popping out of the drain, seeing the daylight..? Thén, you are dead sure the drain is open. Btw, I drive the car for years without the anti bugplugs. These are a 'solution' for a non existing problem, and what's more, they might create one. (Clogging !)

[@Reventon2012]

Thank you sir! How often, in general, should this be done?

[@nman2563]

Unfortunately I have not heard of any recommended schedule. Worth doing at least once every three months if the car spends a lot of time outside, especially in dusty conditions. I hear it is mostly finer dirt (not usually leaves or debris) that gets into the drains and clogs them up.

[@glenglene8473]

can you use compressed air from the top?

[@theninja250]

Does water only fill the drain when top is down, or even if it is up and out in the rain? Thanks, any response would be appreciated.

[@nman2563]

Dust and water enter the drains whether the top is up or down. Though of course it is unlikely that you would leave the top down in the rain.

[@Paradyski]

Is this could be the reason ( blocked draines ) that is causing water getting into battery compartment ?

[@YZFMANIAC08]

Yes for sure. On of the first things I checked when buying a second hand z4

[@brainstorm99]

Is this problem only on E85? Has it been fixed for the E86 2006-?

[@nman2563]

My apologies - I got it wrong in the video. The E85 is the convertible and the E86 is the hard top for all years. Unfortunately the problem still occurs in the 2006+ models.

[@MrPoliceinhelicopter]

hello I've a question: there is a drain hole also in the left side? thanks

[@nman2563]

MrPoliceinhelicopter Yes there is a drain hole on both sides. The motor side drain on the left is the most important to maintain

[@MrPoliceinhelicopter]

nman2563 thanks so much

[@jeremiahporter7647]

WELL GOD DAMN THANK YOU!!!

[@lukey2603]

i have a serious problem, my z4 wont start and i think the controller unit for the fuel pump is broken. do u have a idea where it is placed in the car, im trying to find it for some hours now but i just cant find it to replace it;/

[@blainegabbertgabonemhofgoa6602]

Fuel pump is inside gas tank. You have to remove the exhaust then the fuel filter then you can get to the fuel pump

[@YZFMANIAC08]

I would leave them out all together, they were originally designed to keep insects out

[@BobbySingh-li5hp]

after removing the grommet/plug was it not better to run some water down to make sure there is no blockages? How would the vacuum help if there is not enough suction to pull out dirt?

[@nman2563]

There was enough suction after I put my finger round it.

[@MrSjeupie]

Hmm, what a pita :/ Thnx for the video; I had no idea where to look!

[@user-ly5tf1sz6h]

Leave it to the Germans for making this so needlessly difficult.

[@honeybarrettcharteredaccou6910]

It's not that difficult, you can simply reach under the car and pull the plug out without, jack or any tools.

[@jefredhotful]

i want to know how to open roof,i want servis motor hyedraulic

[@wlh227]

+Jef Redhot the entire roof needs to be removed. Take 2 individuals that know what they are doing about 3 hours total.

[@bbuucc]

It will clog up, destroy radio electronics in trunk ,power motor for top and flood into car..be warned!!!

[@ironboard6]

lol just jack up the car and put your hand up where the plastic hole is, don't need to remove the wheel or any plastic trim, why make it so hard??????

[@nman2563]

I mention that in the video.

[@KhoaNguyen-xj6gk]

If you can not jack up the car, open the plastic trim will be easy to access and it takes only 5 minutes

[@theninja250]

Question, why not remove the drain caps and keep them off so water cannot build up and possible fill top motor or trunk?

[@nman2563]

theninja250 I believe they are there to prevent bugs from climbing in. Some owners have removed them and reported no problems.

[@thisisadebrown]

You could bond some kind of filter mesh over too

[@nman2563]

The plug is meant to act as a valve rather than a filter. You want dirt to pass down through it but not the other way. You also want something removable so you can clean out the hole.