Water keeps leaking somehow in the passenger floor every time it's rains. [Archive] - Bimmerfest - BMW Forums

: Water keeps leaking somehow in the passenger floor every time it's rains.

06-08-2012, 01:16 AM
its weird because nothing else gets wet but the passenger side floor.I had my mechanic check the drains in the sunroof along with the ones under the hood.He says they aren't clogged and as I'm in a wheelchair it's hard for me to check myself.What else do you think the problem can be?

06-08-2012, 09:48 AM
i had the same problem and never found out what the problem was, many threads on here talk about the same thing and no answer, atleast i havent found one

06-08-2012, 03:22 PM
Search button is your best friend..........

Anyway, common problem with E65/ E66. Leak is originating from clogged microfilter drain hole on passenger side.....

Read ENTIRE thread below;


Especially from Post #15.

06-08-2012, 04:19 PM
I had that problem it ended up being my sun roof wasn't closing properly.

06-16-2012, 01:32 AM
I had the same issue where water will pool on the floor rest of the left passenger seat. Sent the car in to an authorised workshop, and they fixed it. Said it was some leaves clogging up some drainage system and told me to stop parking under trees and clear the dead leaves and twigs. Cost me about 150 USD to fix it.

07-03-2012, 11:48 AM
Thanks for the input guys.I honestly have been super frustrated trying to find a solution.I've brought it to 2 shops who both said they cleared the drain.Yet still getting flooding.About to read into the above link to see if i find anything.

07-03-2012, 05:34 PM
What about the sunroof drains?? Check the flow there as well.

08-05-2014, 03:37 PM
The link can't be found. How do I check the drain?

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spyders 745li
08-05-2014, 04:05 PM
Their is a tis on this subject. Also many post on clearing sunroof drains. Google is also a good friend

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08-06-2014, 10:59 AM
The micro filter drain the above poster is talking about, can be accessed by removing the rear section of the passenger front wheel well liner. The drain flap gets blocked with debris. If that's what it is(semi common), its tricky to track. Water running off the windshield drains below the the microfilter housings. If the drain on the passenger side is blocked, water will build up around the electronics box under the passenger side microfilter. There is a drain on the bottom of the e-box that has a check valve, which doesn't seal in standing water. Water leaks past the check valve up into the e-box. The e-box has a fan to to cool the electronics. The fan circulates air in through a duct above the passenger footwell in the interior. This is the path the water will take.(Im a BMW master tech btw)

Tell them to run water around the e-box/passenger microfilter housing. If water backs up around the ebox, this is your problem. Just cut the flap off the drain behind the wheel well liner and clean out the debris.