Cowl vent maybe stuck open?
 

I can’t decide if what I’m experiencing is normal or unusual. I took my speedometer out of my SC last week to have it sent out and repaired. While it was out, I took the car out for a ride or two. While doing so, I noticed two things.

1). While driving it, I get a fair amount of air coming through the open dash hole (vacated by the missing gauge). It’s even more air when I have the windows open.

This is something that might be totally normal, but I honestly don’t know. Driving around without a gauge in the car is not something I’ve done before.

2). Along the same lines, my oil pressure and temp gauge has started to fog up. This isn’t an issue I’ve noticed in the past either. I know that’s a fairly common issue on our cars, but seeing as I haven’t noticed that before and knowing how much airflow I’m seeing, I’m wondering if it’s connected.


Which leads me to wondering if I might have an issue with the cowl vent, or elsewhere up front, letting in that air. Im considering trying to get at the vent/blend doors on the firewall, but haven’t gotten there yet. I’m not getting air out of the vents themselves, only behind the gauges.

Am I barking up a normal tree here? Or is it likely there’s something going on?

The opening for routing A/C lines and the steering shaft isn't perfectly sealed, so if there are any openings between the firewall and the cabin you'll get airflow into the trunk and cabin while driving. If you open the smuggler's box in the trunk you'll be able to see it.

Normal. I had the tach out for repair one spring and the car was borderline undrivable in cold weather until I stuffed the hole with an event t-shirt I found in the frunk. 30 degree air blasting right in your face is unpleasant.

A poorly adjusted front hood, or worn out seal contributes to this issue. Rob

All of the above, plus I put black duct tape over the slots in the bottom of the dash to cut down on cold air into the cabin. Look up under there and you will see the slots and several other holes you can block to reduce cold air. As others have said, you need to make sure the frunk doesn't have gaps and holes that let air come in. Seal those up too.

I also rebuilt the air/fan box to replace the rubber seals on the flapper doors to further reduce air when the flappers are closed.

TBH, it's crazy how many potential leaks/holes there are in the frunk. Missing wire grommets, bad hood seal, bad fresh air seal, under the smuggler's box, the front condenser fan intake hole, etc.... Phil Swift would have a field day in there. :)