BMW Z3 2.2i 2002 Roadster - Water in the boot passenger side

[billy_fleg]

Hi everyone,

So last few weeks was driving and suddenly the alarm started going off on the road! Initially thought there was an issue with the electrics and due to a bad connection as it was intermittent and stopped after a few times. Continued driving and after a few days same thing happened.

Reading through the forum, I found that the tilt switch in the boot on the passenger side of the boot (behind and below the trim) was FULL of water. This seemed to trigerr the alarm when water was covering the tilt switch.

I managed to dry the area and when dry the problem was resolved.

I tried today to find how the water enters that zone in the boot. I therefore removed the trim and spilled around 3 litres of water with the boot closed and the open to try to find how the water finds its route to that area. Surprisingly I did not manage to identify any leak in the boot and there was no water in the boot while dropping the water.

Initially I thought that water was entering via the rear headlight but that does not seem to be the case. Any ideas from where can water enter in there ? Also does anyone know what is the black plastic and what is its purpose ? This seems be the only possible route for water to enter while driving but even that to me seems unlikely.

Would welcome your views - cheers.

 

[t-tony]

Commonest leak there is the aerial grommet, directly above where the water was.

Tony.

 

[Bampz]

Totally agree with Tony , aerial grommet most likely cause , best from main dealer about £10/14 pounds and when fitting a drop of faith liquid helps ( other washing up liquid available )

 

[Eddie Zedder]

The 'black thing' is a vent. It relieves air pressure when closing the boot lid / doors. You will find that has a thin covering of rubber on the outside that is hinged at the top.

 

[billy_fleg]

Commonest leak there is the aerial grommet, directly above where the water was.

Tony.

Tony thanks - will check it tomorrow. Is it difficult to replace ?

 

[t-tony]

Don't think so, never did one on my Z3.

Tony.

 

[t-tony]

Have a look here @billy_fleg It's German but pictures speak a thousand words.

View: https://www.youtube.com/watch?v=DXetOmiB7AM


Tony.

 

[Bampz]

Easy enough to do just be careful of the bulbed bit on the end of the earial amplifier where the aerial screws into as can be a bit fragile , a bit of fairy liquid helps by lubricating the grommet for ease of fitting

 

[Joss]

I'd go with Tony's suggestion too, but fwiw my brake light was the source of my boot leak (found out when my neighbours left a note about the alarm going off -joys of on street parking away from your house) I made a gasket out of some sort of double sided 3m foam about 1-2mm thick

 

[billy_fleg]

Thanks chaps. Inspected again the car and also threw water above the the grommet and there is no leak from there. Any other suggestsios ?

 

[billy_fleg]

I'd go with Tony's suggestion too, but fwiw my brake light was the source of my boot leak (found out when my neighbours left a note about the alarm going off -joys of on street parking away from your house) I made a gasket out of some sort of double sided 3m foam about 1-2mm thick

Did you see water in the boot as well or only at the boot corner on the passenger side where the tilt sensor is ?

 

[Joss]

Did you see water in the boot as well or only at the boot corner on the passenger side where the tilt sensor is ?

I only looked in that corner, as I was having issues with the alarm

 

[billy_fleg]

I only looked in that corner, as I was having issues with the alarm

Thanks - so presumably was rear break light as opposed to the third on in the middle of the boot ?

 

[Oddly Godly]

I had the same issue with water in the passenger side of the boot causing the alarm to sound. The first time the alarm went off was a year earlier. Mine i think was the aerial grommet. The water may build up over months or even longer so it may be a tiny leak. I put black silicone over some cracks in the grommet and have now replaced and fixed my aerial which had previously been snaped off. Keep checking for another build up of water it may be like mine a small leak that went unseen. When I poured water over my car it was practically impossible to get any to enter the boot. Also worth checking the plastic rear window surround hasn't become untucked.

 

[Joss]

Thanks - so presumably was rear break light as opposed to the third on in the middle of the boot ?

No - I did mean the third light. also is the car parked on level ground?

 

[billy_fleg]

No - I did mean the third light. also is the car parked on level ground?

Thanks - yes it parked on level ground.