Mk4 leaking water to the drivers footwell area after big rains

[Dinoplex 3]

Hello, my lhd mk4 leaks water to the driver footwell and there were big rains for 2 days and there was probably like 250ml of water on the rubber carpets that i evacuated. The car just came back from the shop from this same problem and shop said they fixed it which they did indeed replace all the hvac gaskets and pretty sure they cleaned the cowl drains as well. Previously it used to drip water from right under the dash on drivers side and also from the lower hvac air outlet at the center but only drip to drivers side never to passenger side. That thick carpet like material that sits under the dash would be soooo wet but right now thats pretty dry, i felt just a slight touch of wetness on that dashboard carpet at the edge where its near the steering column but it was very little wetness. I felt much more wetness in the section where the fender is, the panel that is left to the clutch pedal. But i never drove the car it was just stationary in the rain, can some rust hole in the fender area cause the water to leak from there into the drivers footwell area even when car is stationary? I also heard that it can sometimes leak from a rust hole under the fuse box area. Or maybe the left fender drain is blocked so its somehow leaking water inside due to that?

Edited April 26 by Dinoplex

[sierra3dr 51]

Might be the heater blower box seal 

[Dinoplex 3]

1 hour ago, sierra3dr said:

Might be the heater blower box seal 

Yeah we also thought it was that and the shop changed it but its still leaking. Which that was definitely leaking too because previously i saw water coming from that area but some other place is still leaking

Edited April 26 by Dinoplex

[Dinoplex 3]

I was speaking with people in a german forum and the guy that owns this channel sent these videos. It looks like it might be due to rust in these locations under the cowl area. They called those locations as "horror corners" 
 

 

 

 

[Dinoplex 3]

Some guy on turkish facebook groups said if i put silicone under the fuse box area i ll be able to stop the leak. The cortinas are ultra popular in here because we also licence produced the taunus tc3 (cortina mk5) under licence from 1985 until 1994 so theres tons of those cars running around here still.

Edited April 28 by Dinoplex

[sierra3dr 51]

On 4/28/2025 at 11:56 AM, Dinoplex said:

Some guy on turkish facebook groups said if i put silicone under the fuse box area i ll be able to stop the leak. The cortinas are ultra popular in here because we also licence produced the taunus tc3 (cortina mk5) under licence from 1985 until 1994 so theres tons of those cars running around here still.

I am going to import one when  I win the lottery  

[sierra3dr 51]

[Dinoplex 3]

2 minutes ago, sierra3dr said:

I am going to import one when  I win the lottery  

But why, they arent very good imo . In turkey they go for 3-4 times cheaper prices than the actual german production models and the later production ones especially from 1990 and onwards like in that picture have lots of sierra bits on them that just make them pretty awful imo. In turkey these are still regarded as a step below the actual german models in terms of quality. In fact when my granddad took our 1975 knudsen tc1 taunus for a repaint in one of the bodyshops here in turkey in the 1990s, the shop owner actually stole a couple bits from our german car to put on his turkish licence production tc3 model simply because the german parts were better.