Leaking Blower Fan?

[sccabrian]

It has rained in the past few days, and I haven't driven my '72 because of a wiper motor issue. Today, I started it up and switched the blower fan on to get some air moving in the cabin, and it was spewing out water. I then noticed a huge puddle on my passenger side floor board. I was wondering where the intake is for that fan, because I think I finally figured out how water was getting in the cabin!

Thanks, Brian

[Ed]

The intake for the fan is directly above it. There is an opening under the cowling (on the outside between the windshield and hood) on the passenger side. Remove the cowling and inspect the area. It's kind of hard to describe but it's about a 6" square with a cover over it. Inspect the lower portion of it. There is caulking around the base and more than likely it's cracked and that's where your water is coming in.

[EScanlon]

Actually, the putty you are referring to is INSIDE the cabin compartment, on the underside of the Cowl Bucket. That's where the fresh air intake for the blower system is.

The problem more than likely is a leak in the flange around that opening.

The hard part will be to inspect all around that flange, since the front part of the flange is so far underneath the cowl lip that you can't see it well without mirrors.

Additionally, repairing it will be a major pain. You won't be able to weld in there without cutting off a bunch of the upper lip of the cowl.

You might be better off by using JB Weld or POR with the Power Mesh, to seal that flange.

The putty (plumber's putty) is a soft pliable seal that permits the two pieces to flex without direct mechanical connection, while still maintaining the seal. It's main purpose is to ensure the connection to the outside. If it were missing, you would draw air in from the back of the dash area and recirculate it, while diminishing the amount of fresh air from the cowl.. Even if the plumber's putty were completely missing, that, by itself wouldn't be the reason for the water coming in.

The flange, where it meets the bottom pan of the cowl bucket, is best described if you imagine a trumpet horn, or a funnel laid on a flat surface. Imagine sealing the edge down. Then at the other end of the funnel (the small end) place a cap that fits all the way around the opening, and extends down below it's top edge. There is approximately 1" of separation all the way around the top of the flange and that cap. This is what prevents water from being driven in directly into the upside down funnel. Only if the water backs up enough that the lower edge of the cap is below water, would you suck water into the fresh air vent. (If your drains were to be that clogged, whenever you would accelerate from a dead stop, the wave surge would cause water to surge out by the kick panels on both sides of the car, and also up by the air vents below the windshield.)

I think you have a hole or two at the point where the flange meets the bottom of the cowl bucket OR you have a missing or holed cap over the flange.

2¢

Enrique

[Dans240z]

My car is missing this part completely. It you look under the cowl there is just a rusty hole. It is probably the rustiest part on the car. A good bit of the metal under the cowl is rot, and I have heard it is a rough fix. I am kind of worried about repairing it.

[Ed]

My car is missing this part completely. It you look under the cowl there is just a rusty hole. It is probably the rustiest part on the car. A good bit of the metal under the cowl is rot, and I have heard it is a rough fix. I am kind of worried about repairing it.

Repairing from the top would be rough because your room is limited. It would probably be easier if you were planning to remove the dash anyway and just plugged the hole with a patch. Rebuilding the intake trumpet would be easiest if you found a donor.