I've read up on the cowl leak problems, I live in Oregon (=lots of rain) and my Stang is my daily driver. I've made covers for the cowl vents, and it continues to leak from the underdash vents... Can anyone shed some light on this please...
Yes, I just changed my windsheild and now it leaks like a seive the way it did before I put new hats in my cowl. I thought I put enough asphault sealer in there but yet, here we are.
answer is yes, i have a leaky cowl vent and windshield, i covered the cowl vent, no lead from there...but then, the corners of the windsheild leak and it runs down the a-pillar and all the way to the floor and tricks me into thinking my cowl is leaking....so pretty much i cnat drive in the rain haha
This exact problem was address in Mustang Monthly a few months back. They say that most people think it's the cowl but its the windshield. The sealer around the window shrinks over time. They say, just take off the moulding and add more sealer around the window and that should fix it.
There are three main areas to check for leaks in the front area of the car. You need to check all three areas separately and in order.
1. Check the cowl for leaks. Pour some water directly into the cowl, making sure not to get water around the windshield area. The water should drain out each side behind the front wheels. You can also look into the cowl area with a flashlight and a hand held mirror.
2. Check the windshield seal. Run some water around the windshield seal, making sure not to allow water to run over the door jambs and door glass. This is probably the greatest cause of leaks into the front of the car. A 35+ year old windshield seal is probably rotted and no longer weather tight. Also, if the windshield has been replaced or pulled recently, after market windshield gaskets are notorious for leaking - make sure to get the FORD seal if you replace the windshield seal.
3. Check the door jambs and door glass channel. Run water directly on the doors, especially allowing water to run down the glass and into the door itself. There are drain holes inside the doors that can get blocked.
Cover the floor boards with some newspaper (it will show even small drips of water very easily) and check after each test.