Water trapped in frame

[Andrew Sheldon]

Returning to my car from my local supermarket I noticed quite a bit of water was coming from under my car and running down the car park, I reckon about a pint or so. My first thought was I had a coolant leak but under closer examination the water was escaping from around one of the the front plastic jack points. We have had some pretty heavy rain lately plus a few days ago I drove through some pretty badly flooded roads so obviously that's what caused it...
My question is how does the water get trapped in that part of the chassis, ie how does it get in there, and has anyone else had this problem. I am a bit concerned because the car could be rusting from the inside out....
I have added a You Tube video of another person with the problem although mine is nowhere as extreme as his.....

https://www.youtube.com/watch?v=Kx7XJ1U1sJc

 

[Tommo61]

Are your drain holes blocked? - the bins can get blocked with leaf debris and fill up with water which overflows into the chassis. They can be easily cleaned by getting a thin drain rod or coat-hanger up into the drain tube from beneath. No need to take the roof off as in this video, but it shows more clearly where they are! https://www.youtube.com/watch?v=CU3HSwL6grM

 

[Andrew Sheldon]

Are your drain holes blocked? - the bins can get blocked with leaf debris and fill up with water which overflows into the chassis. They can be easily cleaned by getting a thin drain rod or coat-hanger up into the drain tube from beneath. No need to take the roof off as in this video, but it shows more clearly where they are! https://www.youtube.com/watch?v=CU3HSwL6grM

I dont think they are blocked as I have only just given them their yearly clean out.. Its the water ingress into the subframe which is puzzling me.. Even if the bins were filling up, which I don't think they are, how would the water get into the frame from the bins.

 

[bigwinn]

Andrew I had similar yesterday- I needed to jack the offside front up and it had been raining a bit

As I did it I was surprised to see a large amount of water trickle from around the jacking point

I assumed it was water stuck in the sill cover?

 

[ph001]

I would suspect the plastic bins overflowing too to cause this. Simple test - with the roof down pour a little water down by the roof hinges on each side, it should immediately appear in front of the rear wheels. If it doesn't, the drains are blocked.

 

[kis]

Really interesting. Wouldn’t the water make its way into the cabin? If it’s that full? That’s what I thought from previous posts. Didn’t think you could have a full on aquarium inside the Zed!

 

[Andrew Sheldon]

Really interesting. Wouldn’t the water make its way into the cabin? If it’s that full? That’s what I thought from previous posts. Didn’t think you could have a full on aquarium inside the Zed!

Yeah ok.... Gonna put some fish in there tomorrow...... grrrr... No the water doesn't go into the cabin. Inside my car is dry as a bone... This is why I am asking... The rear drains to the hood motor have been regularly cleaned.... I am kinda bamboozled....

 

[Andrew Sheldon]

I would suspect the plastic bins overflowing too to cause this. Simple test - with the roof down pour a little water down by the roof hinges on each side, it should immediately appear in front of the rear wheels. If it doesn't, the drains are blocked.

Yes thank you, I will try that but the rear drains have only been cleared about 2 weeks ago. I will poor some water down there and check for the flow..... Having said that how does the water get into the sub frame from the rear water bins....... ?? check out the vid to see the problem..

 

[Andrew Sheldon]

I would suspect the plastic bins overflowing too to cause thi

Andrew I had similar yesterday- I needed to jack the offside front up and it had been raining a bit

As I did it I was surprised to see a large amount of water trickle from around the jacking point

I assumed it was water stuck in the sill cover?

dont think it is trapped in the sill covers but in the subframe itself... not sure how the Z4 is constructed that is why I am asking.. My old 2006 car is immaculate and it would be a terrible shame if it rusted from the inside out, Im sure you feel the same....

 

[kis]

Really interesting. Wouldn’t the water make its way into the cabin? If it’s that full? That’s what I thought from previous posts. Didn’t think you could have a full on aquarium inside the Zed!

Yeah ok.... Gonna put some fish in there tomorrow...... grrrr... No the water doesn't go into the cabin. Inside my car is dry as a bone... This is why I am asking... The rear drains to the hood motor have been regularly cleaned.... I am kinda bamboozled....

What I mean is that if the roof drains are blocked, then many people report water coming into the cabin.

The subframe itself isn’t sealed so it’s interesting. i.e. if water got in from a hole somewhere, it should be able to get out from another hole (lower down in the frame).

Where is the sound coming from? Could it be inside the doors? These are sealed with a membrane? Although like most other parts there are holes lower down for water to egress from... Have you tried removing the jacking points? In the video that’s where the water was stored? They can be removed completely, just as part of solving the water problem, then you can put them back on.

 

[Andrew Sheldon]

Really interesting. Wouldn’t the water make its way into the cabin? If it’s that full? That’s what I thought from previous posts. Didn’t think you could have a full on aquarium inside the Zed!

Yeah ok.... Gonna put some fish in there tomorrow...... grrrr... No the water doesn't go into the cabin. Inside my car is dry as a bone... This is why I am asking... The rear drains to the hood motor have been regularly cleaned.... I am kinda bamboozled....

What I mean is that if the roof drains are blocked, then many people report water coming into the cabin.

The subframe itself isn’t sealed so it’s interesting. i.e. if water got in from a hole somewhere, it should be able to get out from another hole (lower down in the frame).

Where is the sound coming from? Could it be inside the doors? These are sealed with a membrane? Although like most other parts there are holes lower down for water to egress from... Have you tried removing the jacking points? In the video that’s where the water was stored? They can be removed completely, just as part of solving the water problem, then you can put them back on.

I haven't got enough water in the frame to create the whooshing sound like the vid... It just kind of trickles out of the jack point when parked at a slight angle.
I am going to drill holes in the centre of the plastic jack point to allow the water to come out more easily. I mean its not a major problem and it seems like a few Z4 owner have the same, like I said I am worried the car may be rusting from within which would be a shame... Thanks for your help btw...

 

[kis]

If you're worried about it, you could take the body panels off? Ensure there is no leaves, silt, etc that's made it's way there. Check all drain holes (in the frame, door panel, etc are flowing freely). Then you should be okay? I do plan on doing this one day myself, this years been a write off... so Zed (and other things) have been neglected!

 

[Ewazix]

It's worth checking the drains at the front, rubbish can build up in the front scuttle under the screen in the engine bay blocking the water drain-off tubes. Water then makes its way down inside the hollow structure to the sills. The first time I cleaned mine out about ten years ago the front drain was full of leaf compost! See this thread for details https://z4-forum.com/forum/viewtopic.php?f=2&t=40973&p=585592

 

[Andrew Sheldon]

It's worth checking the drains at the front, rubbish can build up in the front scuttle under the screen in the engine bay blocking the water drain-off tubes. Water then makes its way down inside the hollow structure to the sills. The first time I cleaned mine out about ten years ago the front drain was full of leaf compost! See this thread for details https://z4-forum.com/forum/viewtopic.php?f=2&t=40973&p=585592

Thanks...I wasn't sure where the front drains were located having owned my z4 for only a year, the rear drains, ie where the soft top motor/pump is housed, gets a regular clear out. They have always been clear, however the drain grommet does seem restricted by its design...

 

[kis]

The grommet is also there to reduce noise... so design is good for just water.
When dirt and rubbish get into the fold, they clog it up. Like with all things, check it (and clean if needed) once in a while

 

[ph001]

I've done several back to back test on road noise with the bungs fitted and removed - there is absolutely no discernible difference. I think the main thinking behind them was to stop nasty bugs / insects getting into the car but it's hardly a problem in the UK. I'd absolutely recommend removing them.

 

[kis]

I've done several back to back test on road noise with the bungs fitted and removed - there is absolutely no discernible difference. I think the main thinking behind them was to stop nasty bugs / insects getting into the car but it's hardly a problem in the UK. I'd absolutely recommend removing them.

Good to know, thanks for your experience

 

[Andrew Sheldon]

Quick update re water in sub frame.. Got my Z4 up on the ramps a day or so after the rain had stopped, its rained here in SW France solidly for around a week. Looked underneath at the plastic jack points and sure enough water was seeping out very slowly from around the tight fitting edges, ( the jack points clip into place snugly) so I drilled 6mm holes in the centre of them and about half a pint or maybe more of water came pouring out.. I checked the bin drains whilst I was about it and they were fine..
Thanks ph001 for your info, I will remove my bungs today...

 

[ph001]

The drains in the scuttle panel under the bonnet definitely worth checking too.

 

[Andrew Sheldon]

The drains in the scuttle panel under the bonnet definitely worth checking too.

Not that clear on how to check the front scuttles... Under the bonnet on the front bulkhead there are 2 rubber flap type things that seem to drain the water, not sure how to clean them out though...