newbie leaky roof questions

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Joined: Fri 22 Feb, 2019 16:17
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  Z3 coupe 2.8

newbie leaky roof questions

Post by albyl » Wed 27 Feb, 2019 20:46

The Mrs has inherited a 99 2.8 z3 that has been stood outside for the last 4-5 years.

I've managed to get it running with an ews delete and a new fuel pump. It's got some air bag issues that I think I've got a handle on now.

The passenger side and to a lesser extent the drivers side footwells are full of water. Are there any achilles heels in the roof/seals? The fabric seems ok and the leccy roof works fine. There are cracks in the rear screen but these were taped up quite well.


Joined: Mon 12 Nov, 2018 17:47
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  Z3 roadster 2.8

Re: newbie leaky roof questions

Post by LaRy » Wed 27 Feb, 2019 21:15

Poor some water over the roof close to the doors. It is common that the big rubber sealing above the side windows are not water tight in the vertical connection against the windscreen rubber sealing. This will also put some water in the seat. In the same area, you will find a small hole in the windscreen rubber sealing, supposed to drain water down (somewhere). Check those things. Check that water will flow down in the small hole.
I've heard that it could also be that you have a lot of dirt in the area where the blower fan is sucking air. In that case you have to remove the plastic part below the windscreen and clean up. But that is just something I've read.
But also another fact, if a car is not used, standing outdoor in different weathers, it will become wet, the car is breathing and the air will make condense. So, maybe no fault at all. After 4-5 years, it doesn't surprise me at all that it is wet on the floor. No molding on the inside of the roof?

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  M roadster S54
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Re: newbie leaky roof questions

Post by Gazza » Wed 27 Feb, 2019 21:16

Usually the leaks come from the top of the screen posts and/or the centre of the section over the side windows.

The roof clamps are adjustable, may just need a tweak.

"Understeer is when you hit the wall with the front of the car, oversteer is when you hit the wall with the rear of the car. Horsepower is how fast you hit the wall and torque is how far you take the wall with you"

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Joined: Fri 22 Feb, 2019 16:17
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  Z3 coupe 2.8

Re: newbie leaky roof questions

Post by albyl » Thu 28 Feb, 2019 07:52

Thanks for the replies.

Will give me something else to check at the weekend :)

Was green with surface mould everywhere inside, outside and under the bonnet but it has cleaned up ok. The foam in the seat base on the drivers seat seems pretty wet. Is there an occupancy sensor mat in the drivers seat as well as the passenger seat? I've had a couple of codes (14 and 20) for the air bags, have cured 20 but 14 keeps coming back even with an emulator on passenger side. Have ordered a new sensor for the passenger seat but wondered if the problem could be drivers seat?


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  Z3 roadster 2.2i

Re: newbie leaky roof questions

Post by Bumpa » Thu 28 Feb, 2019 09:27

Mine had seriously wet floors too, and being a late model had the yaw sensors under the carpet. They didn't like swimming so cost me some money to replace. Most of my leaks were from (1) a poorly fitted windscreen, and (2) through the door. The windscreen really needs removing and resealing, but for now I have used non-setting sealer to keep the rain out. The barrier in the door is a sort of thin foam and mine had split and was in a generally poor condition. I have made a plastic sheet to supplement it and now the car is dry inside. Drying the under carpet foam was not a simple task!

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  Z3 roadster 2.2i
Location: Basingstoke

Re: newbie leaky roof questions

Post by wonderloaf » Thu 28 Feb, 2019 21:47

I've also had water coming in under the plastic moulding below the windscreen that you mentioned. If you remove it there's also like a plastic fence around the blower unit which is meant to seal against the bulkhead metal work to stop the water getting in, except in my case it didnt. So used plumbers mait to seal all around the fence which solved it.There's also a butyl type seal between the windscreen and plastic moulding (along the bottom of the screen) that can lift or degrade, I'm just about to re-seal this (again) with some butyl strip bought on the 'bay.
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  Z3 roadster 1.9

Re: newbie leaky roof questions

Post by Brittas » Fri 01 Mar, 2019 08:42

Door membranes can cause water to come in to foot well. Pop off door card and check /reseal with silicone sealant. They are a real weak flimsy foam like material.

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