Water come into my cabin....no idea from where..

[moots]

Look carefully the door edge, it should have some water mark there.

To check whether the water come from the door seal, close the door and spray water to the door, check the carpet wet or not.

aisey...don't lar check laidat.....carpet wet got stinky stinky smell wor......
pour water with garden hose on the window with the door OPEN.
if you see water coming out between the door card and the door frame,then your water barrier is not sealing properly.if it IS sealing properly,the water will drain out at the 2 drain holes right at the outer edge of the door's extreem ends.

 

[jaleeks23]

Suggest to check drainage at the engine bay, ECU area, underneath the aircon filter. I had this problem before for my E39, left rear footwell wet. Drainage blocked, so somehow water went into passenger cabin. Another problem is windscreen. Another problem is if the aircon filter box been removed, check if installed overlapping correctly.
How I test
1) lift up carpet
2) close everything and spray water onto windscreen (can see water flow to rear footwell, then bring to mech to check and found drainage block due to dried leaves and all the dirt)

 

[sewell]

moots and BMW7833 is correct. mine also have the same problem before. re-seal it back with new seal and never wet again.

 

[BMW520]

i have the same problem too but water from map light...i fill in silicone between the roof & front windscreen. Now awaiting for heavy rain to test the effectiveness

 

[gendong]

Having the same prob, but not as bad. Water trickling in during heavy downpour rear left passenger side. Suspects door trim that's not properly aligned causing the inner rubber lining to be out of shape.