Cause of rust shock tower/strut tower: bottom welding seam passenger side

[weighttransfer]

Hi,
I have visible rust on the bottom welding seam of the front passenger shock tower/strut tower and i cant for the life of me figure out where the water comes from that is making this rust. There is only rust on the bottom, and it seems there is (hardly) no rust on the drivers side tower.


Also the rust seems to creep up a bit (2-4cm) towards the front of the car, which makes me think the water is coming from the front top of the tower.

Here a few pictures of someone who had rust at the same spot but then a lot worse:
https://forums.m3cutters.co.uk/threa.../#post-2441431
(2 last pictures of the first post)



I can imagine that it rusts fast with little water as the engine heats up the metal accelerating rust.


Im not sure if water comes from the outside of the tower or the inside, it makes sense from the inside as otherwise the engine would evaporate the water quickly. Also i used a cheap endoscope and it looks like there is some moisture on the inside towards the back of the seam. The car hasnt been driven in the rain for 3 weeks. I did clean the wheel wells manually though so this might be an indication that the water came from the wheel well in the shock tower.


I can think of the following origins of the water:


- Coming in through the bottom round hole in the shock tower
- water coming from very loose/old weatherstripping of the engine bay.
(Ive ordered new weatherstripping for this so i hope this is the cause)


- Coming from the wiper fluid reservoir, which leaks if its quite full (new lid did not help to stop this leak)


- Coming from the whole where the brake line comes up in the engine bay from the wheel well. This rubber thing that seals it is quite loose.


- Water splashing up from the street


- Through one of the holes in which the white clips are inserted that hold the wheel well liner or small hole next to it at the top of the wheel well.


- Through a loose welding seam at the top of the inside of the wheel well.




Is this a common problem, can somebody tell me what usually is the origin of the water so i can stop the leak?


thanks!

[weighttransfer]

anybody?