Paint and Body water spot on passanger side

[alutwon]

this leak is driving me nuts. it only happens under heavy rain and it's dropping from under the dash almost towards the front, not from the firewall. it also only happens when Im driving the car, like air is pushing the water. just wondering is anyone has had experience with this.

 

[silverlx50]

Nope. Nice thing about water is you can usually get under and see where it dripped off and trace it up since gravity takes it downwards. Especially in these old cars where everything that isn't in plain view has a thin coat of dust on it.

 

[Haste347]

Have a look under the car. Do you still have your inner-fender wells? Some underbody coating might take care of any small holes and fix your leak.

 

[KRUISR]

Can't see above the puddle, but is it under the dash? If not, could be windshield seal.

 

[alutwon]

yea I haven't had a chance to look under there, I washed the car today and no water spot. it only happens after heavy rain AND while the cars moving. make me think air is pushing the water maybe through vent in the cowl.

 

[7991LXnSHO]

1st Gen Mustangs commonly have rot in the cowl area. Checking what is under the crown vent plastic cover might be ugly, but is a good idea on a car that’s likely at least 30 years old. I am trying to remember for sure, but I think my 79 had a cowl vent on the drivers side kick panel, but not the passenger side because of the dealer AC. The cars have to have a way to drain out the water that flows into the area. If those drains are clogged or slow, or the seam sealer is cracked, I can see water under pressure getting in.