Getting fumes in the cab real bad

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Cruisingram

Cruisingram

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My 1968 dart four door is missing a lot of stuff under the dash, but I don't know what belongs there, so I don't know exactly what it is- I know there is supposed to be an outside vent system, with some levers or something that is supposed to let fresh air in? When I go through the car wash, it blows the soapy water right in ! Anyone have a pic or diagram of what is supposed to be there? I am getting pretty bad engine fumes in the cab, and the exhaust system is tight, and I need to fix this ASAP
 
Are the vent doors closed?. Is there a grommet missing on the firewall?
 
toolmanmike said:
Are the vent doors closed?. Is there a grommet missing on the firewall?
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I am not sure there are any vent doors at all LOL- can you take a pic or have a pic of what I should be looking at? It's been so long, I have no idea what I should be looking for anymore on this subject.
 
Sorry, my 2 Mopars are locked up in storage for the winter. You should be able to find a photo on the net. There is a door on each side under the dash.
 
The hood seal at the back of the hood could be gone. That would allow stuff from under the hood to permeate the cab through the fresh air vents under each side of the dash.
 
Demonracer said:
The hood seal at the back of the hood could be gone. That would allow stuff from under the hood to permeate the cab through the fresh air vents under each side of the dash.
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I am betting this is true. I just wish I knew what they are supposed to look like LOL.
 
Check the gasket where the fuel filler goes through the trunk floor, and also check the filler tube for rust. Mine was rusted through!
 
Cruisingram said:
My 1968 dart four door is missing a lot of stuff under the dash, but I don't know what belongs there, so I don't know exactly what it is- I know there is supposed to be an outside vent system, with some levers or something that is supposed to let fresh air in? When I go through the car wash, it blows the soapy water right in ! Anyone have a pic or diagram of what is supposed to be there? I am getting pretty bad engine fumes in the cab, and the exhaust system is tight, and I need to fix this ASAP
Click to expand...

There are only two places that (should) let air into the "cab" from the outside--the cowling These are an obvious round hole in each corner on the "roof" of the cowling. Right side connects with the heater, and left has a dedicated fresh air vent with a large obvous door down by your shin. Ditto for the heater, that vent is built into the heater

Fumes, I would check the entire pass compartment for leaks. If you have created entrances into the body for various things start there. Missing seat belt/ seat mount bolts, missing / torn shift boot, unplugged holes in the firewall AND LEAKS INTO THE TRUNK. This includes a missing/ torn trunk lid gasket, the fuel filler gasket, any other holes from runs up into the trunk

As you travel down the road, the rear of the car vacuumes air/ exhaust fumes up into the rear area around the car. This is why on a dirty/ snowy road, the rear bumper/ deck gets dirty. This same process sucks fumes into holes in the trunk

Try putting a bright bare lamp bulb in various places in and under the car, then look "through" the car for shining light

Photo I found on the 'net shows the cowl vent holes

3a6d5def-bb9f-42b4-b380-cd1b5b21ae5d_zps2ukciy6n-jpg.jpg


Driver side vent box if yours is missing

0330121746a-jpg.jpg
 
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jos51700 has a point also, the fuel tank grommet & the seal to the fuel neck in the trunk could be hosed up. And/or the trunk weather stripping.
 
Nice pics & commentary 67Dart273, I guess that's why they keep us old farts around.
 
Buddy drove a 396 C10 pickup from ND to Cali with a bad fuel cap gasket. I guess the fuel tank is behind the front seat or something and he had a headache for a week after that stinky road trip. Didn't ask what the fuel bill was. Gas fumes sounds like a fuel leak. Exhaust is different...quite a few gaskets ie. Steering column. Firewall grommets, exhaust leaks.......
 
67Dart273 said:
There are only two places that (should) let air into the "cab" from the outside--the cowling These are an obvious round hole in each corner on the "roof" of the cowling. Right side connects with the heater, and left has a dedicated fresh air vent with a large obvous door down by your shin. Ditto for the heater, that vent is built into the heater

Fumes, I would check the entire pass compartment for leaks. If you have created entrances into the body for various things start there. Missing seat belt/ seat mount bolts, missing / torn shift boot, unplugged holes in the firewall AND LEAKS INTO THE TRUNK. This includes a missing/ torn trunk lid gasket, the fuel filler gasket, any other holes from runs up into the trunk

As you travel down the road, the rear of the car vacuumes air/ exhaust fumes up into the rear area around the car. This is why on a dirty/ snowy road, the rear bumper/ deck gets dirty. This same process sucks fumes into holes in the trunk

Try putting a bright bare lamp bulb in various places in and under the car, then look "through" the car for shining light

Photo I found on the 'net shows the cowl vent holes

View attachment 1715695436

Driver side vent box if yours is missing

View attachment 1715695438
Click to expand...

That drivers side piece is completely missing!
 
The first thing I would look into is excessive blow by filling the engine compartment with crankcase fumes.I had this happen with a plugged up PCV system om my Valiant wagon. If your exhaust is tight there is no other cause for fumes other than this
 
Gasoline fumes in the cab can be caused by a couple of items
  1. Fuel filler vent line in trunk
PXL_20210223_004405606.jpg


PXL_20210223_004429225.jpg

  1. Fuel leaking in the engine compartment with missing hood seal, being sucked into the cowl vent grill.
PXL_20210223_004803645.NIGHT.jpg


You were asking about the vents in the car.
Driver's side
PXL_20210223_004939506.jpg



Pass side
PXL_20210223_004638776.jpg
 
Are you getting "engine fumes" or Gasoline fumes? The original post says engine so fooling with the gas tank venting isn't going do much to help this if it's engine fumes
 
valiantwagonguy said:
The first thing I would look into is excessive blow by filling the engine compartment with crankcase fumes.I had this happen with a plugged up PCV system om my Valiant wagon. If your exhaust is tight there is no other cause for fumes other than this
Click to expand...
Good advice here as well, I will definately look into that as well. Lot's of this stuff I would have thought about 20 years ago with these cars, but I have been out of the game so long! I am missing both those vents, the hood seal too, and the vent on the fuel is bad too. Damn, I got it everywhere.
 
valiantwagonguy said:
Are you getting "engine fumes" or Gasoline fumes? The original post says engine so fooling with the gas tank venting isn't going do much to help this if it's engine fumes
Click to expand...

It has been hard to nail down- thought it was exhaust- and it was at first, fixed the leak on the exhaust, and now we get just an occasional wiff- which tells me the fuel vent actually may be the culprit. It's worse with the front windows down, better with the rear windows down. some gas fumes smelled, some oil leak smell as well. Very small sign of an oil leak around the valve cover I am fixing this weekend.
 
Honestly guys you been a massive help here, I am going to look at all these areas very closely, i really, really suspect that gas filler gasket.
 
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