Water can come in the door for several reasons.
In the old days cars had rain channels (long, thin U shaped grooves that went the length of the roof of the car)
above the door but these cause wind noise at speed and are not aerodynamic so they were got rid of. Now modern cars rely
totaly on the rubber between the car door skin and the frame of the car to keep out water. car doors also have rubber seals around the car glass
, a sheet of plastic that goes between the car's interior door trim and car door to keep water out and drains at the bottom of the car door.
If any of these fail then water will come in the car.
Can you easily slide a playing card between the car door and the rubber seal?
If you can then it might be due to three things:
car Door Rubber worn out
When you push against the car's door rubber with your finger does it spring back? If it does not then
it will not form a good seal and probably needs replaced. Same goes for any car door rubber that is broken, split or falling apart.
car Door Rubber not staying on
Had a van with a sliding door that made a lot of noise and leaked water. The problem was
that the car's door rubber was not staying where it was supposed to stay as the glue that was holding it has dried up. A little bit of glue
and the car's door rubber stayed where it was meant to and the leak went away.
car Door out of alignment.
As cars age the hinges and brackets that support the car's door wear down until the car's door does not close
as it should which can take it out of alignment with the rubber seal. This can also occur with a car that has been badly repaired
as the car's door no longer fits the frame of the car. A car's door latch that is loose will also cause this as the car's door does not lock in a lined up position.
Does Water appear on the inside beside the car's Door Glass?
As rubber ages it dries out and eventually can no longer stop water getting through. These are obvious leaks as the water appears beside the car's door glass
Does car's Door Trim appear Wet?
Maybe the car's door drains are blocked. These are slots at the bottom of the car's door. If the cars' door trim is pulled off,
a protective plastic sheet should be there.
If the sheet is not there it could cause water to leak in and this sheet should be replaced by a piece of plastic cut to size with holes to allow switches and screws.