Modifying roof motor housing with a drain hole?

[srhutch]

I considered drilling a hole but thought that would allow water to get in should it become blocked even at a low level. Once it's wet, the water would soak into the padding and carry on rusting.

I decided to seal the casing with silicon sealant so that even should it become completely submerged, it should be water proof. That and keeping on top of the drainage should mean it will last at least another 10 years

My thoughts to, either seal 100% or remove as putting a hole in it will only allow water in.

 

[Georgio]

I seem to remember that the original problem with the housings was that the motor was wrapped in sound foam before being put into the housing which should have then been sealed properly before fitting.
No doubt the sealing properly part was dropped somehwere either through time issues or plain laziness.
So consequently water gets in soaks into the foam, stays there and then quietly rusts the motor away.
So to be honest drilling holes in the hope that the foam dries out before the motor rusts is probably not the best tactic.

Probably spraying the entire motor with WD40, sealing in a plastic bag and then siliconing the outer case to within an inch of it's life would be recomended to save a repeat performance on motor replacement.

 

[srhutch]

I seem to remember that the original problem with the housings was that the motor was wrapped in sound foam before being put into the housing which should have then been sealed properly before fitting.
No doubt the sealing properly part was dropped somehwere either through time issues or plain laziness.
So consequently water gets in soaks into the foam, stays there and then quietly rusts the motor away.
So to be honest drilling holes in the hope that the foam dries out before the motor rusts is probably not the best tactic.

Probably spraying the entire motor with WD40, sealing in a plastic bag and then siliconing the outer case to within an inch of it's life would be recomended to save a repeat performance on motor replacement.

was the other way round, the insulation was added for face lift models, but when the drains blocked the insulation fills up and traps the water in.

 

[benlumley]

I considered drilling a hole but thought that would allow water to get in should it become blocked even at a low level. Once it's wet, the water would soak into the padding and carry on rusting.

I decided to seal the casing with silicon sealant so that even should it become completely submerged, it should be water proof. That and keeping on top of the drainage should mean it will last at least another 10 years

Yeah - that was my concern too (water coming in through the hole more than out). I had kind of decided to go the hole route before I started.

But when I took the old one apart, the box was full of water - despite it looking like the old one was sealed too (tape though, not silicone). It was very rusty smelly water too, so I reckon it had accumulated over a while, and had no way to get out - the motor had been sat in it for ages. The soft top drains weren't completely clear, but the were still draining pretty quickly - more than enough for normal levels of water from rain/washing.

So my logic was that if the old housing had the hole, this water could have drained out and motor wouldn't have failed so soon. So based on that, definitely decided on the hole option. I did seal the joint up well with silicone too.

All based on supposition - as said above, we'll have to wait another few years to see which approach works best, and whichever approach you take, keeping the drains clear is the main thing.

As a footnote - whilst testing, I did notice that the as the various hydraulic lines get pressurised/depressurised, they sort of flex a bit - wondering whether over time this causes any seal to break a little and allows water in.

 

[Liam-O]

I seem to remember that the original problem with the housings was that the motor was wrapped in sound foam before being put into the housing which should have then been sealed properly before fitting.
No doubt the sealing properly part was dropped somehwere either through time issues or plain laziness.
So consequently water gets in soaks into the foam, stays there and then quietly rusts the motor away.
So to be honest drilling holes in the hope that the foam dries out before the motor rusts is probably not the best tactic.

Probably spraying the entire motor with WD40, sealing in a plastic bag and then siliconing the outer case to within an inch of it's life would be recomended to save a repeat performance on motor replacement.

was the other way round, the insulation was added for face lift models, but when the drains blocked the insulation fills up and traps the water in.

My prefacelift motor had the insulation

 

[Lillywhite]

Within 12 months of the Zed being launched in August 2003 BMW had found the need to issue a Service Information Bulletin to all dealers about the problem of water getting into the housing and basically they were recommending that the housing be sealed with a butyl cord and waterproof duct tape.

http://www.justanswer.com/bmw/5e5mp-bmw-z4-roadster-3-0si-z4-conv-top-hydrolic-motor-water-da.html

 

[benlumley]

I seem to remember that the original problem with the housings was that the motor was wrapped in sound foam before being put into the housing which should have then been sealed properly before fitting.
No doubt the sealing properly part was dropped somehwere either through time issues or plain laziness.
So consequently water gets in soaks into the foam, stays there and then quietly rusts the motor away.
So to be honest drilling holes in the hope that the foam dries out before the motor rusts is probably not the best tactic.

Probably spraying the entire motor with WD40, sealing in a plastic bag and then siliconing the outer case to within an inch of it's life would be recomended to save a repeat performance on motor replacement.

was the other way round, the insulation was added for face lift models, but when the drains blocked the insulation fills up and traps the water in.

My prefacelift motor had the insulation

My post facelift had it - could be that yours had already been replaced, or at least removed/worked on?

 

[benlumley]

Within 12 months of the Zed being launched in August 2003 BMW had found the need to issue a Service Information Bulletin to all dealers about the problem of water getting into the housing and basically they were recommending that the housing be sealed with a butyl cord and waterproof duct tape.

http://www.justanswer.com/bmw/5e5mp-bmw-z4-roadster-3-0si-z4-conv-top-hydrolic-motor-water-da.html

That sounds like what mine had on it, so adds up. As above though, it was still flooded!

 

[Lillywhite]

That sounds like what mine had on it, so adds up. As above though, it was still flooded!

I believe all face lift models (built after May 2006) had the improved sealed housing but this didn't stop water getting in and corroding the motor as many have found out so I was happy for my indy to drill a hole in the bottom of the housing, as they have done in the past, on my housing when replacing my hood motor last month. Just need to keep that main drainage hole clear of c**p and not park near any trees etc.

 

[gr3z]

That sounds like what mine had on it, so adds up. As above though, it was still flooded!

I believe all face lift models (built after May 2006) had the improved sealed housing but this didn't stop water getting in and corroding the motor as many have found out so I was happy for my indy to drill a hole in the bottom of the housing, as they have done in the past, on my housing when replacing my hood motor last month. Just need to keep that main drainage hole clear of c**p and not park near any trees etc.

Only just got my Zed all is working fine at the moment but fancy cleaning out the drainage hole, where is it?

 

[Lillywhite]

Drainage holes are located behind the rear wheels. Obviously with the wheels removed these holes can be accessed and any crap cleaned out. I understand that a quick blast with compressed air may do the trick.

 

[gr3z]

Drainage holes are located behind the rear wheels. Obviously with the wheels removed these holes can be accessed and any crap cleaned out. I understand that a quick blast with compressed air may do the trick.

Cheers... I get my new wheels delivered tomorrow so the wheels are coming off anyway I shall give the a blast with some compressed air, can you only purge back to words the motor. Is there any way of seeing if my motor has water in?

 

[Lillywhite]

.... can you only purge back to words the motor. Is there any way of seeing if my motor has water in?

I believe that all you can do on the passenger side where the motor is. On the drivers side, with the roof down, you can see into the void and I noticed some water in there when I shone a torch and with a long knitting needle I unblocked the drainage hole and water came out near the back of the wheel. On the other side the drainage hole is obscured from the top. Without taking the top off there is no way you can check on the condition of the motor and plastic housing.