rust - ugh

[Sean F]

Little surprise I got over the weekend after chipping away at an odd looking area where the tunnel meets the passenger footwell. Was covered over with filler and POR. I can't imagine this will be fun to repair. Any thoughts?

[Tom F.]

As an East Coast rust connoisseur, I would say that it looks like there may be more trouble. What is the chassis number? I ask because I would be more optimistic that the rust is localized if your car were a Porsche build chassis (911 110 xxxx) than a Karmann built car (911 112 xxxx). The Porsche built cars of this time period had galvanized floor pans, longitudinals, etc., whereas the Karmann built cars did not.

This particular rusting might have started with a poorly installed aftermarket A/C unit.

[RSTarga]

there are also little holes all the way down the underside of the tunnel which originally had little rubber plugs with a tiny hole. If these get plugged the water seeps into the tunnel/floor seam.

[Sean F]

while we're at it, what is that tube with the cover in the smuggler box right in front of the tunnel?

[edmayo]

Sean, the tube was used with a gas heater, it recirculated the heated air in the cabin back to the heater. That's why your rear tunnel access cover has vent slots normally covered with cardboard. When the heater was installed the cardboard cover was removed allowing the air to recirculate down the tunnel back to the gas heater. After 72 (or was it 73?) when the gas heater was no longer an option the tunnel covers lost their vent slots.

[Tom F.]

What Ed said. Let me know if you want to sell the rubber cover. I'm making do with a 3M Deluxe Electrical Tape box on mine! It fits perfectly.

[Sean F]

ah, got it. Thanks.

Might be willing to part with the cover. Based on the first look at the damage, that tube might have to come out. will let you know.

[Tom F.]

Sean, the tube was used with a gas heater, it recirculated the heated air in the cabin back to the heater. That's why your rear tunnel access cover has vent slots normally covered with cardboard. When the heater was installed the cardboard cover was removed allowing the air to recirculate down the tunnel back to the gas heater. After 72 (or was it 73?) when the gas heater was no longer an option the tunnel covers lost their vent slots.

Ed, my May production 73 has a solid tunnel cover. My July 71 production car has a slotted cover.

[orange911]

I am 99% sure that the slotted covers were also used on factory A/C cars to recirc air from the rear as well. Tom, did your 73 have A/C?

[Tom F.]

No A/C on my 73.