ryan_89_mustang

My car is letting water in somewhere, but I don't know where. It is running behind the fire wall sound deadining and pooling up on the floor board. So far I have got the windsheild redone($140), That was leaking, I thought this was the leak when I bought the car so it was no big deal to pay $3200 for....big mistake.
Last week I took the cowl panel off and found some holes, which I fibreglassed(I know not the right way but I can't weld and you would not be able to weld in the tight space).
It is not comming from the floor since the car has not been drivin in the rain, This has all come in while the car was sitting.

Does anyone know where the water is comming from Or have a suggestion to figure it out. I am just comepleatly lost I have been trying to fix this ever since I bought the car a month ago. I have only drivin the stang 200kms in a month. I just want to get her on the road.

mjr46

best way is remove seat so you can lay down on the floor...get in the car and have a hose running on top of the car and look for the leak.....I spent 3 hrs last week doing this on a mercedes sl convertible/ removable hard top car......it sucks but it's the only real way to attack the situation and win

Tony71502

Make sure its not ur coolant that is leaking out of the radiator core. When cores fail they tend to leak exactly where you have specified.

You have have already ruled this out if you know for a fact theres no antifreeze in the water.... Or your coolant level has not dropped.

ryan_89_mustang

I do not belive it is the heater core. Since This is happening when the car is parked and the farthest it has moved was across the street from my neihbours garage with the heat off. It is on the drivers side, Im afraid to take up the pass side again.

r.barn

Water can get in under the plastic cowl cover.
There are holes for it to run in thru down there.

Tony71502

Ahh , if its on the drivers side then it is definatly not the heater core.

Btw coolant flows through the core when the thermostat opens up. Turning on the heat just turns on the electrical blower under ur dash.

ryan_89_mustang

Ya I know there are holes but I am unsure where the hole run through. I have had the plastic cover off and fibreglassed the holes that were in the the bottom. And then undercoated it to seal it all. This is the first rainfall since I have done this, I do not have a garage and a canadian winter is approaching so I really don't know what to do . I can't think of any other possible spots for the water to come in through.
Its comming from the back of the firewall underlay the outside rubberpart is dry and the back side is soaked. There is no coolant it is pure water.

mjr46

actually coolant is always flowing through the heater core as the inlet side is hooked directly to one of the pump output ports and from the intake there is a 90 degree elbow called the coolant bypass port that bypasses the t-stat and goes to the pump

ryan_89_mustang

So can it leak with the car off then?

mjr46

it could as coolant is still in the heater core as it remains constantly with coolant.....but it is usually on the passanger side as that is where the core is located and coolant has a slimy feel to it......take a dry paper towel and dab it on the wet area if it comes back clear it's water..if it has a slight green tint to it..it's coolant..but I doubt your core is leaking..you just need to do what I said in an above post and run water over the car while being inside to look for the leak