I have a 1970 Cutlass, and I believe the fresh air vent door is not closing all the way, maybe due to bad vacuum line or junk in the way causing it to stay open.
How is the best way to get to that door, behind the fender well or behind the kick panel?
Any help would be appreciated.
Thanks, Frank

 

I assume your car has AC? If so, you might start by removing the pass side door sill plate or at least the front 3 screws & then the screws for the kick panel. There should be 2 vacuum hoses plugged in behind there. Maybe with a light you can see what the problem is.

 

Thanks OPR, for the quick response..........will try that tomorrow.
Frank

 

Yes OPR, it has a/c........and I've had engine noise, I think, coming through all a/c vents and it's rpm affected without driving and no blower motor on, been trying to track it down for months.

 

The air door in the passenger kick panel is not a door to let fresh air in - it is a door to suck air OUT for recirculation.
There is a second door in the plenum, reachable from above, that opens to recirculate and closes for fresh air.
I believe that it is normally closed by spring pressure and only opens when there is vacuum.

You should not be able to get any kind of air coming in through the right hand side kick panel if the system is working.

- Eric

 

Eric, thanks, but I don't know where the other door is.........and you say I should be able to get to it from the top........under the hood I take it?
I hope my picture comes in.........is the door in this picture?

 

Eric, here is another pic, I don't know why this is rotating the pics.

 

Unfortunately, I was wrong. I was thinking of cars from a different Division, which do have two separate air doors.

Olds uses one air door, with two vacuum lines to it, and routes the air into the blower slightly differently.

The only air door is the one in the kick panel, which you can remove from inside the car, after removing the kick panel.
It has two vacuum lines, each of which move it in a slightly different way (I believe vacuum is applied to one line for recirc, to both for fresh air).

If you've got an air leak, there are probably leaves and crap blocking something, so if you take it apart, you will probably find the problem.
Be sure to test the movement of the valve at different heat / A/C settings, to be sure it, the lines, and the vacuum switch all work.

- Eric

 

Thanks, that sounds much clearer...........will be on this today.
Frank

 

Scott and Eric thanks, you were both right..........got to the air vent, removed the 5 screws and got it loose but it won't come out........I have pulled it and pushed it, but it doesn't want to come out more than 1/4" or so, like it's tied to a duct or something??

Eric I checked the vacuum, there is vacuum at the vent but it is stuck closed, the vacuum tugs on it and it wiggles it but it is frozen in the closed position. I was going to replace it but I'm thinking I might leave it in that position rather than replace it since that is not the noise source problem, using my electronic mechanics stethoscope to check??

The noise I'm chasing after is not coming from that vent........it is a gurgling air sound that goes up with the rpm in all 4 a/c vents........even removed the vacuum line from under the hood and plugged it and the noise is still in the a/c vents??

Might be time to seek out a mechanic with a smoke machine to seal up the car with a vacuum source in one window and a smoke wand under the hood to see what the heck is the leak source??

Frank

 

Frank,
At the firewall end of that passenger kick panel, it is screwed to the body with 3 screws. That's why it won't come out. On the flapper door there is a small nut & bolt. Maybe loosen that to see if you can move it manually?
You might google a vacuum diagram for your car & find the other diaphragms in the AC system. Remove the hoses one by one & see what happens?
Good luck.

 

With regard to water sounds, consider a blocked drain valve in the bottom of the evaporator box.

- Eric

 

Ok, thanks to both of you..........I'll keep digging till I find it.
Frank