Water leaks in M4 Convertibles

[Hoppyumr]

Does anyone know for sure if they ever redesigned any portion of this "drainage system" through the rear quarter panels under the back side windows and out the bottom of the car with different trim or holes actually included in the right place to allow actual drainage from the factory? OR does it still affect later model year cars 17, 18, 19?

https://f80.bimmerpost.com/forums/sh....php?t=1454918

https://f80.bimmerpost.com/forums/sh....php?t=1270371

I tried looking under my car at the trim shown in the YouTube video and it doesn't really look the same, even from a different vantage point.

[porshah]

Had an E93, never had any water issues. Have a F83 currently, now water issues.

[Hoppyumr]

Originally Posted by porshah

Had an E93, never had any water issues. Have a F83 currently, now water issues.

What year is your car? Does your trim look like in the video?

[porshah]

F83 is 2016

[Fat Goose]

There are two plugs on each side of the car, just need to remove them and you shouldn't have any issues. There is a SIB for the issue, I also drilled a larger hole to allow the water to drain more effectively (probably not needed), the culprit is definitely the design of the drain plugs. There are supposed to prevent things from going up but it just clogs with dirt and prevents water from draining. need to pull off some underbody panels and then just unscrew the drain plug. You will see how clogged and dirty they are.

[Hoppyumr]

Originally Posted by Fat Goose

There are two plugs on each side of the car, just need to remove them and you shouldn't have any issues. There is a SIB for the issue, I also drilled a larger hole to allow the water to drain more effectively (probably not needed), the culprit is definitely the design of the drain plugs. There are supposed to prevent things from going up but it just clogs with dirt and prevents water from draining. need to pull off some underbody panels and then just unscrew the drain plug. You will see how clogged and dirty they are.

Yah, I guess I'll pull the panel s under my car off entirely to get a better look. They don't seem to pull down quite the same as in the video, but I'll give it another look.

Here is the SIB mentioned above:
https://static.nhtsa.gov/odi/tsbs/20...47023-9999.pdf

[Fat Goose]

I followed that SIB, and it was very easy once under the car

[Beach3um]

My plugs are removed ,and holes are bigger.still have water after heavy rain. More in drivers side rear the passenger. How to fix?

[NashvegasR]

I sold my F83 M4 after moving to Oregon from California because it leaked, floors were wet all the time... and they had no clue how to fix it at the BMW dealers (you would think a Seattle and a Portland OR BMW dealer would have dealt with this) .... Mine leaked at the rear quarter windows every single time it rained.

[N44RP]

Worth it

[instalher]

pull the back seat out, pull the driver side rear quarter panel off and inspect what they have engineered. This should not be that big of a deal for a bmw dealership to make an amendment to the rubber liner on the rear glass. It needs to me 1 mm thicker so it will seat better to the frame trim.. Orrrrrrrr take that plug out and toss it.... trim out the underbody cardboard, trim out the rockerpanel... now the water has a strait shot from the interior to the exterior.... WAIT.... Now you have to make a 2 inch "Z"shelf that will glue to the underframe of the car then go down about 3mm to 4 mm, then about 3 inches towards the rear of the car so the drain hole is now completly covered, but now no dirt or grime will get in but the water will easliy roll out toward the rear of the car.. make sure that there is a tiny bit of egress from front to back so the water will drain properly, easy.. we due this all the time when we put speakers in the floor under the front seat of cars and dont want the magnets to get dirty or wet but they need to still breath,, works perfect.. anyone got a c.a.d. machine.. make these for 2 bucks and sell them for 49.95 a pair. You will sell a ton!!