I just pried out 6 plugs that were on the inside body panel of this 81 van. Two of them were full of water. Why, is this done. I know I've done this before and I think it's been on other Mopars. I mean this is an open invitation for rusted rocker panels. I've always wondered why; someone who knows tell me please. I assuming it's ok to leave them unplugged, and to clean them out, if they get clogged with debris

 

I was once told they were there to allow drainage during painting and then final wash-down at the factory. I've never bothered to confirm that, but it made sense.

 

Thanks alloro-seems like that's possibly what I remember hearing several years ago. But it doesn't make sense to keep these holes capped when there's water in there.

 

The caps also help keep rain water out. It's a catch 22 situation.

 

My first task on a "new" vehicle is to remove those plugs. You're right all they do is trap junk. Better to get in there with a hose and flush everything out. When dry, I blow in my fave.......... Bee's wax (toilet seals) disolved in varsol mixed with old ATF. If you haven't already done so, drill a hole into the front fender (at the door opening) and blow more in there. Rustproofers traditionally ignore this space 'cause air to the heater moves through there and it stinks, for a few days. Also keep the drain holes at the fender, front bottom cleaned out so the fender can drain properly. All the water that enters through the cowl vent grille exits those holes, or is supposted to.