Strange (FACTORY) Holes in Trunk Lid

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Treblig

Treblig

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Does anyone know the purpose of the two holes in the bottom of the trunk lid ('69 Barracuda, Fastback). I've had issues with an exhaust smell when driving and I found these two hole on either side (and below) of the license plate (see pics). At first I thought they might be holes for a rubber bumpers but they don't hit against anything. Then I thought that maybe they were weep holes for water to get out of the trunk lid (when closed) .....but how could water get in the trunk lid?? Either way these holes allow exhaust to get sucked into the truck area then into the whole car AND IT STINKS!!! In the pics you can see these small square rubber pieces I have glued to the hole to keep exhaust from entering. If they are weep holes to drain the trunk lid how did the manufacturer keep exhaust fumes out of the car???

Confused,
Treblig
 

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Either drains or maybe rubber "bumpers" went in there would be my guess.
 
They are about 1/4" (maybe a little less) in diameter. My car has no rust anywhere so it can't be rust holes. They are perfectly cut (punched holes) exactly the same distance from the center of the trunk. If they are factory condensation holes it makes no sense. Why would the factory deliberately put holes in the trunk so that exhaust could get sucked into the car and make customers complain. Every car made like this would cause every car (barracuda) to smell like exhaust after driving around for a while. Everyone who bought a car like this would keep taking it back to the dealer with a complaint of exhaust smells in the car. It makes no sense. I appreciate all the comments but somebody must know what these are for. If I plug them (like I have) then the trunk will eventually rust out (no way for moisture/water to escape) . If I leave them open then I small exhaust.

puzzled,
Treblig
 
There use to be a popular anti rust treatment they would apply to cars. Ziebart was the name of the company. They would drill holes like that to spray the ant rust liquid in areas that they couldn't other wise get to. They would plug the holes afterward with those body plug looking plugs. Maybe this was a body panel that was on a car that was treated? They would drill holes in door jambs also and then use those plugs.
 
Those holes are factory holes, my 67' fastback has the same holes in the same location they are drain holes for any water that would accumulate in the deck lid
just don't see how any exhaust fumes could get up through them unless your running really rich
 
Cudascott, You're making a little sense. My car does seem to run a little rich. But, even if it wasn't running rich exhaust fumes (non-rich fumes) would still be sucked into the car. When I got the car it had a real strong smell of exhaust when I would drive around. Once I found that my trunk seal wasn't sealing completely I installed a newer soft seal on the trunk lid (as you can see in the pics). My car already had a new trunk seal on the body. Anyway, even with the new seal on the lid I can just barely smell exhaust now. So I know that some exhaust is still seeping into the car. I'll take some pics tomorrow so everyone can see the holes from the inside of the trunk, the inner trunk lid and the trunk are wide open on the inside. The car has no coating (at all) in the trunk lid, it's still bare metal, nice and clean with just a hint of minor surface rust (very, very minor). I know that when a car goes down the road the pressure inside the car drops and if you have any type of exhaust leak near a hole or crack in the body the low pressure inside the car will suck the exhaust into the cabin area. This usually happens when you have a leak under the car but I have all new exhaust and have had it checked for leaks by experts (it's sealed up tight). But at the rear bumper there are the dual exhaust pipes where there is definitely tons of exhaust. When you guys (and girls) see the pics from the inside of the trunk you'll understand why it makes no sense. I can understand the factory putting weep hole in the trunk to keep it from rusting but those same holes also allow fumes to enter the car (if your exhaust comes out at the rear bumper).

not as puzzled now,
treblig
 
Treblig,
I do see how exhaust fumes would get in the cabin through those holes but they are tiny. You could do a simple test to see if that's where it's coming from by
Applying a dab of clear silicone on them and drive. It would very easy to remove
the silicone once it dried it would pull right off
Cudascott
 
Yes, that is a good method to try. But as I've been looking around the rear end of the car I also see other small holes (tiny areas, not really holes) like where the bumper bolts go through. I need to seal off all these tiny crevasses near the exhaust pipes. After I seal all the tiny areas I'll try your idea to see if I need to plug the holes or leave them open. I know that one of the reasons my trunk has not rusted is because of the weep holes so I hate to plug them. I guess I could also tape or glue pieces of thin plastic sheet over the large opening on the inside of the trunk lid so I could leave the holes open??? This would keep any exhaust inside the trunk lid and out of the car. How do you keep the car from running rich?? I'm running an edelbrock carb and intake with 302 casting heads on a 318 stock motor (very mild cam).


treblig
 
What is the CFM of the carb your running? Incorrect air to fuel ratio is a huge culprit
of a rich condition.
 
600 CFM,

I did have to change the metering rods sometime ago to fix a hesitation/stumble when accelerating while cruising.

Treblig
 
yeah I would tape them to seal the hole and see if it makes a difference. Another place for exhaust fumes to enter is around the tail light assy's. They have a thick gasket that gets warn out over time or may not be tight enough to seal properly. Be careful tightening them as the studs do break.
 
Here is a 1967 trunk lid that shows the holes.

attachment.php
 
strange gasket seen in the picture. It may be keeping the trunk from sealing properly. The only gasket should be on the body that the trunk seals against.
 

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That should be about right for the carb sounds like it just needs properly tuned.
Good eye rockyjs on the mysterious gasket I too wonder what's up with that the
only gasket should be on the body not the lid
 
The extra gasket on the lid is soft seal gasket I added to seal the large gap that was between the lid and the body seal. By large I mean about 1/8" -3/16". After chasing this exhaust leak for a year I finally got really mad and climbed into the trunk/package area and had a friend shine a bright light along the outside trunk seal area. With the trunk closed and locked (and me inside) I saw massive amounts of light coming through mostly on either side of the bottom but also along the part that runs up around the tail light area of the seal (not the tail light seal). I also saw plenty of light coming through the two FACTORY holes!!! I tried different foam thicknesses of material until I figured out what thickness was required to make it seal. The round hollow soft seal you see in the pic was perfect for making the seal complete. I know it doesn't belong there but all the trunk to body lines are really good and adjusting the lid would mess up all the body lines (gap between trunk and body). I know that your supposed to adjust the trunk hinges to make the seal correct but it would really mess up my body lines (trunk to body gap). I will also try to adjust the idle screws to see if I can lean it out a little. This car is a survivor, no rust anywhere, no body damage, no wrecks, no dents and all original (except for some mods I have made (59,000 original miles). I love driving the car but the exhaust fumes took all the fun out of driving around. I have stopped 95-98 percent of the leaks so I'm simply going for perfection. If I leave the holes open I really don't know if it will let exhaust into the car but I would think that some exhaust has to enter as the pressure inside a car is always less than the pressure outside the car when you're going down the highway...that's why you need a good trunk and tail light seal. Even the bumper bolts seem to have large gaskets on then to keep the exhaust from being sucked into the car.

treblig
 
Can you get a close up picture of your trunk gasket. If it is the proper one it should seal tightly the trunk to the body. I have seen a couple different ones stated as being for barracuda but only one is really correct. I do see (picture) that your gasket is set on the lower lip of the trunk it should be down on the flat part in front of the lip.
 

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I'll go out and take some pics in a while. As far as I know it is the correct gasket. But I'll get some close-ups so maybe someone can point out a problem with what I have.

thanks,
Treblig
 
The seal is before or ahead of those holes. What little fume that enter those holes should be captured inside the lid.
What do you have for interior panel ?
 
cudascott said:
Treblig,
I do see how exhaust fumes would get in the cabin through those holes but they are tiny. You could do a simple test to see if that's where it's coming from by
Applying a dab of clear silicone on them and drive. It would very easy to remove
the silicone once it dried it would pull right off
Cudascott
Click to expand...


Why not just cover them up with tape for the test? Easier to remove than silicone.
 
Treblig said:
I know that when a car goes down the road the pressure inside the car drops and if you have any type of exhaust leak near a hole or crack in the body the low pressure inside the car will suck the exhaust into the cabin area. This usually happens when you have a leak under the car but I have all new exhaust and have had it checked for leaks by experts (it's sealed up tight).
treblig
Click to expand...


This comment triggers something in my mind. Have you heard of "exhausters"? They are used to release the positive pressure from inside the passenger compartment while the blower is working. If you put a fan on the top of a jar and turned it on, it would fill the jar with air, then when the jar is completely full of air and can't hold anymore, there will be a back pressure against the fan as there is no more room to put more air into the passenger compartment. So to eliminate this effect in a car from putting similar back pressure against the blower when the interior fills with air, they put what is called "exhausters" somewhere on the car to release pressure from the inside of the car to the outside so the blower can keep pushing more air into the car. The exhausters can be in many places and also hidden. On the original Grand Cherokees, the exhausters were styled into what looked like a vertical vent on each rear pillar behind the rear side glass window and just before the tailgate. They are basically a rubber sheet or flap hung from the top on the inside. Then gravity keeps the rubber flap covering the hole, then when the inside pressure builds up, it opens the bottom part of the flap to let the air out of the interior so the blower can push more in. On the second generation Grand Cherokee they moved them and incorperated them into the tail lights. That is those "vent holes" in the side of the tail lights. On the 2nd generation Barracudas, they are built into the doors. The inlet is on the bottom interior of the door and the outlet is on the back of the door towards the bottom (if I remember correctly) you have to open the door to see it. I just tried to walk out to get some pictures, but there is too much snow between me and the cars and spare doors to get some pictures (and now there is snow inside my shoe and my feet are cold and getting wet).

My point of all of that is: Could your exhauster "flaps" have been removed and could be letting air in from there? Check to make sure that they are there and straight not peeling back (distorting) from age.

Maybe someone could get some pictures of theirs to post (who don't have to dredge through snow to take them).
 
RedFish said:
The seal is before or ahead of those holes. What little fume that enter those holes should be captured inside the lid.
What do you have for interior panel ?
Click to expand...


The trunk has large factory holes made into the interior of the trunk lid. The trunk lid is totally porous when it come to air. There is also a hinged panel between the trunk area and the passenger compartment but exhaust fumes and air can pass through numerous openings between the body panels. I'll show this in the pics that I'll take. I went outside a few minutes ago to take some pics but the battery in the camera was dead so I'm charging it while I write.

Treblig
 
krazykuda said:
Why not just cover them up with tape for the test? Easier to remove than silicone.
Click to expand...


Yes tape would be easier, right now they are plugged with silicone and rubber tape. But if these holes are critical to prevent rust in the trunk lid then I need to figure a way to keep them open. Also there are holes in the trunk lid near the front just below the back windshield, I'll show these in the pics. It's almost as if Mopar designed the trunk lid to take air (and water if it's raining) into the front of the trunk as you go down the road and this way the air could flow through the lid. But with the large factory openings on the inside of the lid there really wouldn't be any flow-through. Pics to follow.

Treblig
 
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