Floor wet after hard rain, driver's side

[First01]

2010 328i.
I'm stumped. Do I need to look at a clogged water drain? And where?


Thanking you in advance for advice. Kind regards

[154e90]

Make sure the lid to the ECU is covered properly. There's a tube that goes from the ECU box to the module area on the fuse box behind the glovebox. I'd expect to see condensation too on the windshield after a rain. The cowl assembly is essential for ensuring water isn't an issue too.

If this is the issue you need to fix it fast. I had a cluster go bad because of water in that box and had a very bad time trying to fix it. All the wires on my ECU had condensation too.



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[apgambino]

It could be the seals that keep water that comes in from the door window from entering the cabin. Check the door sill and underside of the door panel after a rain. If it's wet, you need to replace that butyl tape seal.

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[First01]

Make sure the lid to the ECU is covered properly. There's a tube that goes from the ECU box to the module area on the fuse box behind the glovebox. I'd expect to see condensation too on the windshield after a rain. The cowl assembly is essential for ensuring water isn't an issue too.

If this is the issue you need to fix it fast. I had a cluster go bad because of water in that box and had a very bad time trying to fix it. All the wires on my ECU had condensation too.



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Thank you. But one question, The ECU is on passenger side so would I get water on the driver's side?
Kind regards

- - - Updated - - -

It could be the seals that keep water that comes in from the door window from entering the cabin. Check the door sill and underside of the door panel after a rain. If it's wet, you need to replace that butyl tape seal.

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Hi,
The door sill has been wet before and it was wet this time too. Drops of water. I don't know what that butyl tape seal is. Is there a pic or a diagram? Door I have to remove the door panel? Kind regards

[White94RX]

Remove the door panel and inspect the "sound insulation", aka the moisture barrier. If it's not 100% sealed to the body of the door around the bottom, and halfway up each side, it will leak water into the vehicle.

[154e90]

Oops :l I misread your post and thought you said passenger side.

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[apgambino]

Thank you. But one question, The ECU is on passenger side so would I get water on the driver's side?
Kind regards

- - - Updated - - -



Hi,
The door sill has been wet before and it was wet this time too. Drops of water. I don't know what that butyl tape seal is. Is there a pic or a diagram? Door I have to remove the door panel? Kind regards

When you remove the door panel you will see a gray foam insulation panel that is attached to the door with butyl adhesive. It is this panel that keeps sound and water out. Sometimes the butyl adhesive dries out and no longer provides a good seal which lets water through. It happened to my 07 335i because (I suspect) it spent its entire life in the high desert. I replaced the gray insulation panels (both sides leaked, ~$35 from ecstuning) as removing it proved tricky and tore the old one. See amazon for the adhesive. The hardest part is removing the old adhesive to have a clean slate for the replacement. The last thing you want to do is to cut corners here and end up with a less than watertight installation. I hope that helps.

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[First01]

Remove the door panel and inspect the "sound insulation", aka the moisture barrier. If it's not 100% sealed to the body of the door around the bottom, and halfway up each side, it will leak water into the vehicle.

Thank you..!

- - - Updated - - -

When you remove the door panel you will see a gray foam insulation panel that is attached to the door with butyl adhesive. It is this panel that keeps sound and water out. Sometimes the butyl adhesive dries out and no longer provides a good seal which lets water through. It happened to my 07 335i because (I suspect) it spent its entire life in the high desert. I replaced the gray insulation panels (both sides leaked, ~$35 from ecstuning) as removing it proved tricky and tore the old one. See amazon for the adhesive. The hardest part is removing the old adhesive to have a clean slate for the replacement. The last thing you want to do is to cut corners here and end up with a less than watertight installation. I hope that helps.

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Thank you so much for the detailed explanation..!

[dworthy]

You can also use a heat gun to re-activate the butyl adhesive if you still have a glob behind the vapor barrier. Normally in order to access the window motor, ect, you have to heat up the butyl sealant to be able to pull the vapor barrier off. I have also used a putty knife to help cut the sealant too.

[First01]

You can also use a heat gun to re-activate the butyl adhesive if you still have a glob behind the vapor barrier. Normally in order to access the window motor, ect, you have to heat up the butyl sealant to be able to pull the vapor barrier off. I have also used a putty knife to help cut the sealant too.

Thank you so much..!